Absolutely Essential For Accurate, Safe, Chamber Work
The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
SPECS: Machined Steel. Size varies with caliber and gauge style. NOTE: Gauges Interchangeable between calibers have same Stock #. .30-30 Cartridges are .219 Wasp, .219 Zipper, .22 Sav HP, .30-30, .32 Win Spl, .32-40, .375 Win and .38-55. .30-06 Cartridges are .25-06, .270 Win, .30-06, 8mm-06, .338-06 and .35 Whelen. Magnum Cartridges are .257 Weatherby, .264 Win, 6.5 Rem Mag, .270 Weatherby, .275 H&H, 7mm Rem Mag, 7mm Weatherby, 7x61 S&H, .300 H&H, .300 Win Mag, .30-338, .300 Weatherby, .308 Norma, 8mm Mag, .338 Win, .340 Weatherby, .350 Rem Mag, .358 Norma, .375 H&H, .416 Rem Mag and .458 Win.
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Customer ratings for FORSTER PRODUCTS, INC. 257 ROBERTS GO GAUGE
Number of ratings: 13
From brownells.com: 13
Average rating: 3.9
Not Good(07/06/2014)
2 piece gauge that comes apart the first time you use it, a poor design and not up to their usual quality. Not one I would buy again!
Unusual headspace gage(08/09/2017)
Brownells located .303 British GO and NO-GO gages. It took a while to get these out-of-stock items, but Brownells kept my purchase record and sent the items when they came back in stock. Today I discovered I now also needed a .303 British FIELD gage, and I am convinced that my FIELD gage will arrive when back in stock. They stick with it. THANKS!!!
NOT useful for Surplus Military Rifles(24/08/2014)
I expected this gauge to conform to Military specification of the Enfield No4 MK1. After purchasing both GO & NO-GO, I found out these gauges give false readings as they are not intended for proper Headspace gauging. I'm hopeful Brownells will accept these gauges in return and provide me with the proper Military Spec gauges.
Does the job!!!!!!!!!!(19/09/2011)
Great tool and very easy to use. You do not have to take the bolt apart to use this tool. Big plus.
Great Tool(20/09/2011)
Great tool! No need to take the bolt apart to use this gauge. Slips right in the chamber. Must have for checking old carbines for service.
Recommended(01/11/2009)
What can I say? They work and the price is right.
Recommended(01/11/2009)
They work and the price is right.
Absolutely essential for a safe build(14/03/2010)
This Forster Field Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the biggest of the three sizes), you have an unsafe chamber headspace and should not shoot your rifle until is it fixed. The only downside is the price, because its a very limited function tool. Bottom line, you need this tool(along with Go and NO-GO gauges) if you are building an AR.
More useful than Foster NO-GO gauge(10/11/2013)
The SAAMI limit is actually 1.4736 so this 1.4696 gauge may prove to be more useful as a NO-GO gauge than a FIELD gauge in many instances (manufacturers often chamber to 0.002" plus over SAAMI mins and this gauge is SAAMI min plus 0.006). The alternative Brownells (Foster) FIELD gauge checks the true SAAMI max limit ("FIELD") of 1.4736 and permits 0.004 more headspace than this gauge.
For further reference, the Foster NO-GO gauge is 1.4696 and only 0.003" above SAAMI min headspace and the Foster GO gauge is at the SAAMI min limit. In my experience, most AR bolts will close on the Foster NO-GO gauge and this "FIELD" gauge may actually be a better test for "NO-GO," unless all your barrels are custom-chambered!
The best solution for checking headspace, post-chambering, is the full set of 11 Foster gauges offered by Brownells. It provides 0.001" resolution over the entire 1.4636" to 1.4736" SAAMI range, which includes any 5.56 specs and limits too. (5.56 headspace specs all lie withing the SAAMI min to max range.)
An absolute necessity for building an AR(14/03/2010)
This Forster NO-GO Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the middle of the three sizes), you may have an unsafe chamber headspace and should try the larger FIELD gauge before shooting your rifle. If you are planning to build an AR, this tool is a must.
Good when chambering but that's all(10/11/2013)
In studying the prints for many 5.56 and 223 chamber reamers and the SAAMI 223 Rem spec, I discovered that headspace gauges and chamber reamers are all over the map. This Forster NO-GO gauge appears check a rather arbitrary point within the SAAMI min to max headspace spec range so one can't draw much of a conclusion based on a gun failing a check with this NO-GO gauge.
More specifically, the min to max SAAMI headspace spec spans 0.010 inches. The Forster GO gauge checks the bottom limit of the SAAMI spec and the Brownells (Forster) FIELD gauge checks the upper limit. Various NO-GO gauges fall in various places with respect to 5.56 and 223 Rem specs, but these intermediate gauges (including 5.56 gauges) all lie between the SAAMI 223 Rem min and max headspace limits.
The problem is this Forster NO-GO gauge checks only 0.003" above the min SAAMI spec. I've learned that barrel manufacturers often chamber their barrels 0.002" longer the SAAMI minimum (the manufacturers use SAAMI min + 0.002" as THEIR mininum manufacturing spec), due to the dangers posed by "tolerance stackup" of parts and insufficient headspace. Given that the Foster NO-G0 gauge is only another 0.001" longer than these barrel manufacturers' min chamberings, it is common for a bolt to close on this Foster NO-GO gauge.
While the Foster NO-GO gauge provides a sensible limit for custom chambering new barrels, its usefulness is very limited for checking existing barrels where a safety check can be accomplished with only a GO and FIELD gauge set. Given where most barrels are headspaced, a NO-GO gauge close to the middle of the SAAMI range would be more useful.
Even more useful is Brownells ".223/5.56 Match Headspace Gauge Set. It can be used to fully assess the headspace of an existing barrel.
An absolute necessity for building an AR(14/03/2010)
This Forster GO Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the smallest of the three sizes), you are good to go. This is an absolute necessity if you are building an AR.
regret buying(26/05/2010)
These gauges are difficult to read what type of gauge it is.the type is so faded and there is no color codeing I spend too much time fiddling with trying to figure out under a bright light and magifying glass if im holding a GO,NOGO or field gauge. Other than that they work.I wish I would have bought gauges that have the easy to read color bands .
Product no.: 319418080 FORSTER PRODUCTS, INC. 257 ROBERTS GO GAUGE Mfr Part: HG0257G757253004421 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Forster Headspace Gauges are essential for measuring chamber length, crucial for safety and accuracy when chambering a new barrel or buying a used gun.
The gauges are made to SAAMI specs with the .257 Roberts GO Gauge being .0005 inch under 7.62 NATO NO-GO dimensions for safety.
Gauges are machined steel, vary by caliber and gauge style, and are interchangeable between calibers sharing the same stock number.
Attributes
Cartridge:
257 Roberts,7 mm Mauser (7 x 57 mm Mauser)
Style:
Go Gauge
Delivery weight: 0.041kgShipping width: 83mmShipping length: 146mm
UPC
: 757253004421
Item details
Made in USA
Product no.: 319022043 FORSTER PRODUCTS, INC. 22 LONG RIFLE GO GAUGE Mfr Part: HG22RIMG757253004605 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319022046 FORSTER PRODUCTS, INC. 22 LONG RIFLE NO-GO GAUGE Mfr Part: HG22RIMN757253004612 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319022049 FORSTER PRODUCTS, INC. 22 LONG RIFLE FIELD GAUGE Mfr Part: HG22RIMF757253004599 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319223464 FORSTER PRODUCTS, INC. 223 REMINGTON GO GAUGE Mfr Part: HG0223G757253004292 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
49.9GBP39£49.90
*
Delivery time approx. 7-14 days. More than 10 pieces in USA warehouse
Product no.: 319223467 FORSTER PRODUCTS, INC. 223 REMINGTON NO-GO GAUGE Mfr Part: HG0223N757253004308 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
49.9GBP39£49.90
*
Delivery time approx. 7-14 days. More than 10 pieces in USA warehouse
Product no.: 319223470 FORSTER PRODUCTS, INC. 223 REMINGTON FIELD GAUGE Mfr Part: HG0223F757253004285 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319306055 FORSTER PRODUCTS, INC. 30-06 SPRINGFIELD NO-GO GAUGE Mfr Part: HG3006N757253004643 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319306058 FORSTER PRODUCTS, INC. 30-06 SPRINGFIELD FIELD GAUGE Mfr Part: HG3006F757253004629 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319308634 FORSTER PRODUCTS, INC. 243 WIN; 7MM-08, .308/.243; .308 WIN, .243-.308 NO-GO GAUGE Mfr Part: HG0243N757253004346 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319308638 FORSTER PRODUCTS, INC. FIELD, .243 WIN; 7MM-08, .308/.243; .308 WIN, .243-.308 Mfr Part: HG0243F757253004322 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418011 FORSTER PRODUCTS, INC. 222 REMINGTON NO-GO GAUGE Mfr Part: HG0222N757253004278 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418040 FORSTER PRODUCTS, INC. 22-250 REMINGTON GO GAUGE Mfr Part: HG2225G757253004544 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418041 FORSTER PRODUCTS, INC. 22-250 REMINGTON NO-GO GAUGE Mfr Part: HG2225N757253004551 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418050 FORSTER PRODUCTS, INC. 220 SWIFT GO GAUGE Mfr Part: HG0220G757253004230 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418051 FORSTER PRODUCTS, INC. 220 SWIFT NO-GO GAUGE Mfr Part: HG0220N757253004247 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418081 FORSTER PRODUCTS, INC. 257 ROBERTS NO-GO GAUGE Mfr Part: HG0257N757253004438 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418082 FORSTER PRODUCTS, INC. 257 ROBERTS FIELD GAUGE Mfr Part: HG0257F757253004414 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418090 FORSTER PRODUCTS, INC. 6MM REMINGTON GO GAUGE Mfr Part: HG0244G757253004360 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418091 FORSTER PRODUCTS, INC. 6MM REMINGTON NO-GO GAUGE Mfr Part: HG0244N757253004377 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418101 FORSTER PRODUCTS, INC. 280 REMINGTON NO-GO GAUGE Mfr Part: HG0280N757253004469 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418110 FORSTER PRODUCTS, INC. 284 WINCHESTER GO GAUGE Mfr Part: HG0284G757253004483 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418111 FORSTER PRODUCTS, INC. 284 WINCHESTER NO-GO GAUGE Mfr Part: HG0284N757253004490 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418120 FORSTER PRODUCTS, INC. 30 M1 CARBINE GO GAUGE Mfr Part: HG0030G757253004209 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418121 FORSTER PRODUCTS, INC. 30 M1 CARBINE NO-GO GAUGE Mfr Part: HG0030N757253004216 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418150 FORSTER PRODUCTS, INC. 8X57MM MAUSER GO GAUGE Mfr Part: HG8X57G757253004698 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418151 FORSTER PRODUCTS, INC. 8X57MM MAUSER NO-GO GAUGE Mfr Part: HG8X57N757253004704 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418160 FORSTER PRODUCTS, INC. 6.5X55MM SWEDE GO GAUGE Mfr Part: HG6555G757253004667 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418161 FORSTER PRODUCTS, INC. 6.5X55MM SWEDE NO-GO GAUGE Mfr Part: HG6555N757253004674 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418162 FORSTER PRODUCTS, INC. 6.5X55MM SWEDE FIELD GAUGE Mfr Part: HG6555F757253004650 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418220 FORSTER PRODUCTS, INC. 30-30 WINCHESTER GO GAUGE Mfr Part: BG3030G757253002847 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418221 FORSTER PRODUCTS, INC. 30-30 WINCHESTER NO-GO GAUGE Mfr Part: BG3030N757253002854 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418222 FORSTER PRODUCTS, INC. 30-30 WINCHESTER FIELD GAUGE Mfr Part: BG3030F757253002830 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418230 FORSTER PRODUCTS, INC. 30-40 KRAG GO GAUGE Mfr Part: BG3040G757253002908 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418231 FORSTER PRODUCTS, INC. 30-40 KRAG NO-GO GAUGE Mfr Part: BG3040N757253002915 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418250 FORSTER PRODUCTS, INC. BELTED MAGNUM GO GAUGE Mfr Part: BG300MG757253002816 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418251 FORSTER PRODUCTS, INC. BELTED MAGNUM NO-GO GAUGE Mfr Part: BG300MN757253002823 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418252 FORSTER PRODUCTS, INC. BELTED MAGNUM FIELD GAUGE Mfr Part: BG300MF757253002809 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 100010713 FORSTER PRODUCTS, INC. 5.56MM NATO COLT SPEC (1.4646") GO GAUGE Mfr Part: HG02231.4646-SP757253992490 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
49.9GBP62£49.90
*
Delivery time approx. 7-14 days. More than 10 pieces in USA warehouse
Product no.: 100010714 FORSTER PRODUCTS, INC. 7.62X51MM NATO (1.6330") GO GAUGE Mfr Part: HG308-1.6330-SP757253992278 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 749003171 FORSTER PRODUCTS, INC. FORSTER HEADSPACE GAGE - FIELD GAGE, 222 REM MAG Mfr Part: HG222MF757253004568 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 749003174 FORSTER PRODUCTS, INC. FORSTER HEADSPACE GAGE - FIELD GAGE, PPC FAMILY Mfr Part: HG0PPCF757253004506 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000022 FORSTER PRODUCTS, INC. 300 BLACKOUT FIELD GAUGE Mfr Part: HG0300F757253992100 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000027 FORSTER PRODUCTS, INC. 300 BLACKOUT GO GAUGE Mfr Part: HG0300G757253992124 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000017 FORSTER PRODUCTS, INC. 300 AAC BLACKOUT NO-GO GAUGE Mfr Part: HG0300N757253992117 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000023 FORSTER PRODUCTS, INC. 6.5MM CREEDMOOR FIELD GAUGE Mfr Part: HG65CRF757253992131 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000103 FORSTER PRODUCTS, INC. 350 LEGEND GO GAUGE Mfr Part: HG350LG757253991301 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000104 FORSTER PRODUCTS, INC. 350 LEGEND NO GO GAUGE Mfr Part: HG350LN757253991295 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430102691 FORSTER PRODUCTS, INC. 6.5 GRENDEL FIELD GAGE Mfr Part: HG65GRENF757253991080 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430102690 FORSTER PRODUCTS, INC. 6.5 GRENDEL NO GO GAGE Mfr Part: HG65GRENN757253991097 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
43.9GBP11£43.90
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Delivery time approx. 7-14 days. More than 10 pieces in USA warehouse
Product no.: 430105157 FORSTER PRODUCTS, INC. 6.5 PRC NO GO HEADSPACE GAGE Mfr Part: HG65PRCN757253990656 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430105156 FORSTER PRODUCTS, INC. 6.5 PRC FIELD HEADSPACE GAGE Mfr Part: HG65PRCF757253990663 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430106386 FORSTER PRODUCTS, INC. 7.62X39 NO GO HEADSPACE GAUGE 1.255 SAAMI Mfr Part: HG762X39N757253990755 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319022050 FORSTER PRODUCTS, INC. 22 PPC, 6MM PPC GO GAUGE Mfr Part: HG0PPCG757253004513 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319306049 FORSTER PRODUCTS, INC. 30-06 SPRINGFIELD GO GAUGE Mfr Part: HG3006G757253004636 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319308630 FORSTER PRODUCTS, INC. 243 WINCHESTER GO GAUGE Mfr Part: HG0243G757253004339 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418010 FORSTER PRODUCTS, INC. 222 REMINGTON GO GAUGE Mfr Part: HG0222G757253004261 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418042 FORSTER PRODUCTS, INC. 22-250 REMINGTON FIELD GAUGE Mfr Part: HG2225F757253004537 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418100 FORSTER PRODUCTS, INC. 280 REMINGTON GO GAUGE Mfr Part: HG0280G757253004452 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418122 FORSTER PRODUCTS, INC. 30 M1 CARBINE FIELD GAUGE Mfr Part: HG0030F757253004193 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418152 FORSTER PRODUCTS, INC. 8X57MM MAUSER FIELD GAUGE Mfr Part: HG8X57F757253004681 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418232 FORSTER PRODUCTS, INC. 30-40 KRAG FIELD GAUGE Mfr Part: BG3040F757253002892 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418240 FORSTER PRODUCTS, INC. 303 BRITISH GO GAUGE Mfr Part: BG303G757253002878 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418241 FORSTER PRODUCTS, INC. 303 BRITISH NO-GO GAUGE Mfr Part: BG303N757253002885 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418242 FORSTER PRODUCTS, INC. 303 BRITISH FIELD GAUGE Mfr Part: BG303F757253002861 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000004 FORSTER PRODUCTS, INC. 7.62X54R FIELD GAUGE Mfr Part: BG762RF757253118029 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 100010715 FORSTER PRODUCTS, INC. 308 WINCHESTER (1.6400") NO-GO GAUGE Mfr Part: HG308-1.6400-SP757253992230 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319000018 FORSTER PRODUCTS, INC. 6.5MM CREEDMOOR NO GO GAUGE Mfr Part: HG65CRN757253992148 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430102689 FORSTER PRODUCTS, INC. 6.5 GRENDEL GO GAGE Mfr Part: HG65GRENG757253991103 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430105155 FORSTER PRODUCTS, INC. 6.5 PRC GO HEADSPACE GAGE Mfr Part: HG65PRCG757253990670 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 430106385 FORSTER PRODUCTS, INC. 7.62X39 GO HEADSPEACE GAUGE 1.252 SAAMI Mfr Part: HG762X39G757253990762 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Product no.: 319418012 FORSTER PRODUCTS, INC. 222 REMINGTON FIELD GAUGE Mfr Part: HG0222F757253004254 The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
Absolutely Essential For Accurate, Safe, Chamber Work
The only way to accurately measure and test the length of the chamber of the rifle. Essential when chambering a new barrel to ensure a tight, accurate, safe chamber. Whenever you buy a used gun, always check the headspace before firing. Forster gauges are made to SAAMI specs. 100-010-715 - This gauge is .0005 inch (5/10,000 inch) under 7.62 NATO specification for NO-GO dimensions for safety.
SPECS: Machined Steel. Size varies with caliber and gauge style. NOTE: Gauges Interchangeable between calibers have same Stock #. .30-30 Cartridges are .219 Wasp, .219 Zipper, .22 Sav HP, .30-30, .32 Win Spl, .32-40, .375 Win and .38-55. .30-06 Cartridges are .25-06, .270 Win, .30-06, 8mm-06, .338-06 and .35 Whelen. Magnum Cartridges are .257 Weatherby, .264 Win, 6.5 Rem Mag, .270 Weatherby, .275 H&H, 7mm Rem Mag, 7mm Weatherby, 7x61 S&H, .300 H&H, .300 Win Mag, .30-338, .300 Weatherby, .308 Norma, 8mm Mag, .338 Win, .340 Weatherby, .350 Rem Mag, .358 Norma, .375 H&H, .416 Rem Mag and .458 Win.
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Customer ratings for FORSTER PRODUCTS, INC. 257 ROBERTS GO GAUGE
Number of ratings: 13
From brownells.com: 13
Average rating: 3.9
Not Good(07/06/2014)
2 piece gauge that comes apart the first time you use it, a poor design and not up to their usual quality. Not one I would buy again!
Unusual headspace gage(08/09/2017)
Brownells located .303 British GO and NO-GO gages. It took a while to get these out-of-stock items, but Brownells kept my purchase record and sent the items when they came back in stock. Today I discovered I now also needed a .303 British FIELD gage, and I am convinced that my FIELD gage will arrive when back in stock. They stick with it. THANKS!!!
NOT useful for Surplus Military Rifles(24/08/2014)
I expected this gauge to conform to Military specification of the Enfield No4 MK1. After purchasing both GO & NO-GO, I found out these gauges give false readings as they are not intended for proper Headspace gauging. I'm hopeful Brownells will accept these gauges in return and provide me with the proper Military Spec gauges.
Does the job!!!!!!!!!!(19/09/2011)
Great tool and very easy to use. You do not have to take the bolt apart to use this tool. Big plus.
Great Tool(20/09/2011)
Great tool! No need to take the bolt apart to use this gauge. Slips right in the chamber. Must have for checking old carbines for service.
Recommended(01/11/2009)
What can I say? They work and the price is right.
Recommended(01/11/2009)
They work and the price is right.
Absolutely essential for a safe build(14/03/2010)
This Forster Field Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the biggest of the three sizes), you have an unsafe chamber headspace and should not shoot your rifle until is it fixed. The only downside is the price, because its a very limited function tool. Bottom line, you need this tool(along with Go and NO-GO gauges) if you are building an AR.
More useful than Foster NO-GO gauge(10/11/2013)
The SAAMI limit is actually 1.4736 so this 1.4696 gauge may prove to be more useful as a NO-GO gauge than a FIELD gauge in many instances (manufacturers often chamber to 0.002" plus over SAAMI mins and this gauge is SAAMI min plus 0.006). The alternative Brownells (Foster) FIELD gauge checks the true SAAMI max limit ("FIELD") of 1.4736 and permits 0.004 more headspace than this gauge.
For further reference, the Foster NO-GO gauge is 1.4696 and only 0.003" above SAAMI min headspace and the Foster GO gauge is at the SAAMI min limit. In my experience, most AR bolts will close on the Foster NO-GO gauge and this "FIELD" gauge may actually be a better test for "NO-GO," unless all your barrels are custom-chambered!
The best solution for checking headspace, post-chambering, is the full set of 11 Foster gauges offered by Brownells. It provides 0.001" resolution over the entire 1.4636" to 1.4736" SAAMI range, which includes any 5.56 specs and limits too. (5.56 headspace specs all lie withing the SAAMI min to max range.)
An absolute necessity for building an AR(14/03/2010)
This Forster NO-GO Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the middle of the three sizes), you may have an unsafe chamber headspace and should try the larger FIELD gauge before shooting your rifle. If you are planning to build an AR, this tool is a must.
Good when chambering but that's all(10/11/2013)
In studying the prints for many 5.56 and 223 chamber reamers and the SAAMI 223 Rem spec, I discovered that headspace gauges and chamber reamers are all over the map. This Forster NO-GO gauge appears check a rather arbitrary point within the SAAMI min to max headspace spec range so one can't draw much of a conclusion based on a gun failing a check with this NO-GO gauge.
More specifically, the min to max SAAMI headspace spec spans 0.010 inches. The Forster GO gauge checks the bottom limit of the SAAMI spec and the Brownells (Forster) FIELD gauge checks the upper limit. Various NO-GO gauges fall in various places with respect to 5.56 and 223 Rem specs, but these intermediate gauges (including 5.56 gauges) all lie between the SAAMI 223 Rem min and max headspace limits.
The problem is this Forster NO-GO gauge checks only 0.003" above the min SAAMI spec. I've learned that barrel manufacturers often chamber their barrels 0.002" longer the SAAMI minimum (the manufacturers use SAAMI min + 0.002" as THEIR mininum manufacturing spec), due to the dangers posed by "tolerance stackup" of parts and insufficient headspace. Given that the Foster NO-G0 gauge is only another 0.001" longer than these barrel manufacturers' min chamberings, it is common for a bolt to close on this Foster NO-GO gauge.
While the Foster NO-GO gauge provides a sensible limit for custom chambering new barrels, its usefulness is very limited for checking existing barrels where a safety check can be accomplished with only a GO and FIELD gauge set. Given where most barrels are headspaced, a NO-GO gauge close to the middle of the SAAMI range would be more useful.
Even more useful is Brownells ".223/5.56 Match Headspace Gauge Set. It can be used to fully assess the headspace of an existing barrel.
An absolute necessity for building an AR(14/03/2010)
This Forster GO Headspace Gauge is a nicely constructed product that performs an often ignored, but very important function. If your bolt carrier group locks into battery against this gauge (the smallest of the three sizes), you are good to go. This is an absolute necessity if you are building an AR.
regret buying(26/05/2010)
These gauges are difficult to read what type of gauge it is.the type is so faded and there is no color codeing I spend too much time fiddling with trying to figure out under a bright light and magifying glass if im holding a GO,NOGO or field gauge. Other than that they work.I wish I would have bought gauges that have the easy to read color bands .