Forster ProductsNATO Chamber Headspace Gage, Rimless, Hardened Steel, Precision Ground

First one I received, the product packaging was open and there was no gauge inside. What the hell. I immediately filed a replacement request and returned the empty packaging with an explanation. Received another gauge within 2 days, also with product packaging open, but at least it was actually there. All worked out in the end and item performed the job I needed at a reasonable price. yay amazon!

These were perfect to check the headspace. And disassembling the BCG was super easy to use them.

Price was right, shipping was fast, arrived on time in a hard secure container perfect for bench storage. This little gage is a must have for anyone building ARs, swapping barrels or bolts requires the use of this little guy, though very uncommon (I've never seen both brand new parts fail in checking thousands of builds), it is possible I reckon.

this gauge worked great for swapping out the barrel on my 223 savage.

Easy to use and great peace of mind.

Call it cheap insurance if your buying a used or are building a custom AR platform rifle, because even if you use only the best made parts and accessories on the market there's always two things to considder, murphies law and there's an oddball in every bunch so even with only the best made parts from the best name brands there's always at least one oddball in every batch that can slip by the inspectors bench. It's cheap enough of an item to make sure your $2000.00 new built custom weapon isn't going to blow apart and maim or kill you or someone else so it's always a good idea to check minimum and maximum and sometimes field gauge test your chambers headspace. When buying a used weapon you definitely want to check your headspace of even the highest end AR rifle because sometimes wear can increase your headspace on your rifle, case and point, I own an Oly Arms complete factory built AR rifle that I've owned for some ten to twelve years and I boughtt both the GO/NO-GO gauges to check out the headspace on my new built rifle and thought just for kicks and giggles I'd check the headspace on my Oly Arms AR and the GO passed fine but imagine my surprise when the bolt closed all the way on the NO-GO test gauge so I was a bit stunned that it failed the NO-GO test because I've been shooting this rifle for over ten years and have put through about 600 to 700 rounds through this rifle and never had a hickup once and I've always cleaned and maintained it as well as swapped out some worn or old parts with newer parts, however I've never removed the barrel or nut or anything else that could effect headspace on the rifle so now I need to order the field gauge to make sure it's still safe for target shooting. Either way you look at it, you need to have a set of these tools in at least the GO & NO-GO set and maybe even the field gauge too just to be safe in the event your rifle fails the NO-GO test because if it fails that test but passes the field test your still in good enough shape for target shooting but not for high accuracy type shooting..BC

These Go and No Go headspace cartridges are meant to give the gun assembler exacting measurements for correct headspace for your gun receiver. No guesswork. Just pure no-nonsense safety to ensure the longevity and security of your new barrels and weapons.Great must have tools for the gun builder.Really glad I bought my set.

Better safe than sorry

Works great arrived quickly