Needs instructions
The smaller gage length equals the minimum SAAMI Headspace. For 300 AAC Blackout it is 1.0789. The SAAMI max headspace is 1.0889 but they give you 1.0849. So... Why is the gage not 1.0889?
The intent is that your chamber must fit the 1.0789. Then, if the 1.0849 also fits, your chamber would be greater than the difference, which is 0.006.
Optimum headspace 3 to 5 thousandths clearance is recommended. So if you have 0.006, that would excessively stretch your brass when fired.
Works great
Zero issued with function of this product. Nice to know all my bolts, barrels passed headspace. Pretty expensive for two pieces of steel.
Might have been improved already but....
I received my 308 gauge set. The Go gauge is as they say is not really needed for new AR platform builds, as you can take firing pin out and just use the bolt, insert a cartridge and twist and it either fits or it does not. If it does not go in the the barrel the extention and barrel were not made by a company that has a clue how to put a barrel and extention together or make a chamber. The No Go, stopped as it should. I noticed that the Clymer gauges have a bevel at base and it appears that you do not need to remove ejector plunger to use gauge. no forcing is needed, if it goes in and stops and does not allow the bolt to turn and lock into battery, then you are good to go. I might add that that bevel might have had an addition that would have been great for AR guys, and thats a recess so the ejector plunger to fit so no amount of force is needed at all. that way plunger would not have to be removed. so in addition to the beveled edge they could have made in base a hole could have been end milled in center of bevel and the gauge could just clip under extractor and then straight with bolt right into chamber. the tools are made with a quality finish and fit, with clearly maked length numbers on the gauges. I strongly believe that there ahould be a 3 pc set as you really should get the "Field" gauge which I purchased seperately, its more needed than Go gauge. at least for the average guy who builds or "assembles" AR platform firearms. because the Field gauge tells you the chamber is way too long and can be dangerous. It is said that some firearms that the no go gauge goes in may still be seevicable but the Field gauge is even longer and that one should not go in at all! All 3 gauges are made of good quality. too bad there is not an less expensive way to make a one time use set. As I may never use these again. and the total was 99.00 , still good insurance for peice of mind. May not have been needed at all really. I purchased a good quality barrel from a reputible company. Its not like I was cuttung my own chamber in a bench rest gun barrel...these barrels are pretty much Plug and play..just torque correctly and you are done yet checking the chamber gave me an idea on the limits of how long a bullet/cartridge I can use in the future in the event that I wanted to reload and use a heavier longer projectile. Although reliaders know you can find that depth buy gently pressing a bullet into an empty case until it stops and you have your max. minus a bit. these are really for "real gun builder" but it is sure good to know that all is well when you use them regardless. you never know when a barrel could sneak through QC at the factory.
MATCH gauges
I bought this gauge set thinking they were just standard .308 Win gauges, they are not. These are match gauges. Now I am slightly annoyed i have to pick up another pair.
7.62x39 Head space gauges
Works great,I like the reassurance knowing my weapon won't blow up.
No good for AK's
When arrived they looked completely different them the pic of the 7.62 x 39. Come to find out they are bases of SAAMI specs (USA Ammo) not CIP specs (European ammo) My AK47 calls for CIP so I sent these back. From the looks the quality looked excellent and I am sure they are just fine for USA ammo specs. I gave them a 4 because it was not noted what specs they were and the pic was misleading because the pic shows a CIP appearance. They are a great company to deal with though.
Not the best but they will work.
Clymer gauges are great but brownell was a little off. There was surface rust on one the gauges. It cleaned up fine but i shouldnt have to deal with it on a new gauge. The "handy, durable plastic carrying case" is a clear endmill/drill case. Over all it will work fine for what I need.
