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Posted: 7/28/2016 10:12:48 AM EDT
| I'm just finished build an AR , the headspace is excessive fails ,no go gage , how can this be corrected , this on a 300 ACC BLACKOUT HBAR barrel. |
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Check with a FIELD gauge. HS is more than desired but is not dangerous unless it fails the FIELD gauge. You may try another bolt and see if it tightens up HS. I had a barrel that Failed the GO gauge but still worked just fine, but the O.C. in me got the best of me and I tried another bolt, passed the GO and No Go then so I was happier. If you have spare bolts around, try swapping a few out and see what happens.
If it passes FIELD test, shoot it. If it fails FIELD, contact the maker for replacement. Or, if this is your only .300 BO and you only shoot reloads, adjust your sizing die to eliminate the excessive HS. |
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Ditto, feild gauge would be the final word, and if it fail such test, then double check the bolt and if not the problem, then barrel would be sent back for a replacement.
Note, you really need to weed out if the problem is bolt, or chamber to begin with. Hence make sure that the bolt is within spec, before you start blaming the barrel chamber. As pointed out, you could adjust your dies for such conditions with reloads, but if factory ammo is run through the rifle, then this will not solve the problem instead. Also to add, with new parts, there is always the burs on the inside of the barrel extension lugs and in some cases, on the back of the bolt lugs that will wear off in a short period, and if the head space is long now, it going to be longer yet once the parts do mate in. I bring this up, since if a rifle is tight on a go gauge, then most of the time it's a problem (burs) that will work it self out quickly as the burs are going to be knocked off isntead. with head space too long on a new build, it going to get worse quickly instead. |
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It is personal choice, but at the price of barrels these days I would not find a barrel acceptable that fails the No-go gage with a bolt that measures .156” from the rear of the lugs to face of the bolt.
As was pointed out if it passes a Field gage it would be safe to shoot, but barrel life may be compromised. |
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Quoted:
It is personal choice, but at the price of barrels these days I would not find a barrel acceptable that fails the No-go gage with a bolt that measures .156” from the rear of the lugs to face of the bolt. As was pointed out if it passes a Field gage it would be safe to shoot, but barrel life may be compromised. |
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Wouldnt a field gauge be more for a rifle with many many rounds on it. Im assuming the OPs build is with new parts. I would be pissed if my new build headspace was gauging as a well used rifle. Quoted:
Check with a FIELD gauge. HS is more than desired but is not dangerous unless it fails the FIELD gauge. You may try another bolt and see if it tightens up HS. I had a barrel that Failed the GO gauge but still worked just fine, but the O.C. in me got the best of me and I tried another bolt, passed the GO and No Go then so I was happier. If you have spare bolts around, try swapping a few out and see what happens. If it passes FIELD test, shoot it. If it fails FIELD, contact the maker for replacement. Or, if this is your only .300 BO and you only shoot reloads, adjust your sizing die to eliminate the excessive HS. |
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Field is Field regardless if the barrel is new or has a million rounds through it. If any barrel fails FIELD then the headspace is dangerously excessive. A new barrel improperly chambered, a barrel fed a diet of excessively hot (over pressure) ammo, or a barrel that is just simply worn out, Field fail is fail.
Damned straight, a new barrel that fails FIELD means the maker has "some 'splainin' to do." |
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