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Posted: 11/12/2012 7:20:38 AM EDT
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I am a newbie here and have used the search function as much as I can and I'm about done with my two twins and would like to check the headspace and have one small question.
Which exact headspace guage do I need just to deem the rifle safe? I know with a no go head space as long as the bolt doesnt close then it meets the maximum requirements. I'm not concerned with extreme precision at this point just want to be sure it's safe to shoot so is the no go gauge all I need to achieve this. Thanks for your help |
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don't even have to search, its a sticky….
http://www.ar15.com/forums/t_3_4/315921_Headspace__Torque_values__and_Barrel_Break_in.html |
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Quoted:
You want the Colt 1.4736 Field gauge. +1 The precision guys will want to argue, but this is the gauge length that is used world-wide to check headspace on AR15/M16/M4 Quote from Bravo Company...... ....A little knowledge is dangerous, but if you must mess around with a headspace gauges get a FIELD gauge. That is the only one you will need. That is the only one you will need. Not just any field gauge, get the NATO one that Colt recommends........ (.1.4736”).......(Brownells #319-418-033). You are not building barrels, you are not fitting bolts. You are in “the field”, and that is your gauge. Double check the measurements on your gauge. I have seen many gauges with text and not marked with a numeric measurement and even mis-marked dimensions. Get rid of them. Just keep the Colt FIELD Gauge |
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Thank you,
Excuse my ignorance but do these still require removal of the extractor? Not an issue just curious. Also, with this one the bolt should close as normal right? If so its deemed safe? Again I'm not concerned with precision at this point, I have other rifles for that I just want to be sure these two guns are safe to shoot. Thanks for your help guys I know it gets annoying seeing the same questions but haven't found the exact answer I've been looking for with the search func |
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Quoted:
Thank you, Excuse my ignorance but do these still require removal of the extractor? Not an issue just curious. You should remove at least the ejector if using the Brownells full rim version of this gauge. I believe Brownells instructions call for removal of both the ejector and extractor. There is a military version of this gauge that has a rebated rim which does not require any removals. They are hard to find lately. Also, with this one the bolt should close as normal right? If so its deemed safe? Again I'm not concerned with precision at this point, I have other rifles for that I just want to be sure these two guns are safe to shoot.
No, this is a FIELD gauge which is a type of NO-GO gauge. The bolt should not close on a FIELD gauge. Edit: Never let the bolt fall (slam) on a headspace gauge. Permanent damage to the gauge can occur. |
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As others have mentioned, your application calls for a "FIELD" gauge. There is little use in checking GO & NO-GO on parts that you are not in total control of unless you are trying to set one up with a tight chamber with hand fitted parts. Otherwise, you really only need the Go & NO-GO if you are actually cutting the chamber.
Your application is simply checking if the assembly is safe to shoot. That is the purpose of the FIELD. If it closes on the FIELD, you have issues with either the chamber, extension or bolt being out of spec. MLG |
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