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Posted: 11/20/2010 2:06:30 PM EDT
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So, I bought a NO-GO gauge.
Today I was checking headspace on my new build and I just wanted to make sure I wasn't doing something real stupid. I broke everything down and did NOT remove the extractor and stuff like the guide says. I put in the NO-GO gauge and inserted the BCG. I couldn't get it to go all the way no matter how hard I tried to push. Instead of using a GO gauge I just put in a Federal XM193 brand new bullet into the chamber and tried to close the BCG into battery and with a little bit of pushing it went in. When I pulled it back it extracted the bullet like it should. Question is, was this stupid (Other than maybe using a live round as a GO gauge) and would what I did confirm headspacing is proper? Thanks. |
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The Go gauge is an accurate instrument to allow you to be sure that your headspace is adequate in length terms of specification. Using an XM193 tells you that your headspace is enough for that specific round, not necessary that it is to spec i.e. that round could be potentially out of spec and it might still chamber. Of course, you could run a whole bunch of different rounds from different manufacturer to tell you that your headspace is more likely to spec, probably the worst thing that could happen to you is you might find some rounds that are to spec may not chamber properly.
For your own use, that is probably an OK shortcut (or was that a longcut?), but you can see why a rifle manufacture would never take that route. |
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Honestly the way you used it you wasted your money. If you do not use a tool correctly, why bother? Most likely your results are good, they sound OK, but really, why bother if you do not intend to use it like the directions tell you?
If you want to do it the right way, remove your extractor, remove your ejector unless you have the make of gauge that has the ejector cut in it, and then check. Clean and dry your chamber and make sure there is no crud, lint, oil, or anything in that chamber at all. Make it squeaky clean. Then, insert in your NO GO carefully and make sure the gauge and your upper are at the same temperature. Don't just 'drop' it in. Now, insert your bolt and lightly push to see if it will close. If it does not, it passes the NO GO test. You now know you do not have excessive headspace. A GO gauge tells you that your chamber is large enough to accept any spec ammo. NO GO tells you you may have excessive head space which can lead to short case life and can be dangerous in extreme situations. For instance, if your bolt closed on a FIELD gauge, do not shoot it any more until it has been checked by someone who really knows what they are doing and the headspace issue is corrected. If your rifle does not close on a GO, it should, that is not usually an unsafe condition. What that would tell you is that some ammo may not chamber. If the ammo were on the large side of spec, and obviously your chamber is on the small side, actually smaller than spec, then large speced ammo may not allow the bolt to close. My 6.5 CSS will not close on a Grendel HS GO gauge, but it has chambered everything I have tried to feed it. It may be just a .001 off on the small side, but that can be enough to keep it from closing on a GO gauge, but will still chamber all but the largest speced ammo. Using a round to test GO tells you absolutely nothing other than it will chamber that round. |
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