View Full Version : Need to know if upper ok to shoot. Advice?
blackjack_03
04-26-12, 17:56
Just completed a new upper using a used colt barrel. Approximate round count about 1500. I don't have gauges so I took it to a local shop. I had a BCM and LMT (both used but under 1000 count) bolt close over no-go gauge. He unwrapped a brand new BCG and it was good to go but he only sells crap so I didn't buy it. He said the barrel is wore out which is hard to believe with a low round count.
I was told if I test fire it to be careful but it should be fine to shoot. It was suggested I buy a new bolt. Since it is a Colt barrel I will buy a Colt bolt sometime soon. Should I wait til I get a new bolt or try it out now?
Does it fail on a field gauge too, or just the no-go?
blackjack_03
04-26-12, 18:03
LMT failed on field and no-go but the BCM only failed the no-go. The BCM is paired with it right now.
davidjinks
04-26-12, 18:13
Is this used barrel your's from another gun or did you purchase it privately used?
Are you sure the guy using the gauges was using the proper ones?
Did he do the gauging properly?
The other rifles are your's that you bought/built new or were they bought used?
Something isn't sounding right about this...
blackjack_03
04-26-12, 18:25
This is my only rifle with using a used part. I'm not sure of the gauging process, he did it in front of me but I didn't get a close look at the gauges he was using. The barrel was bought used in a private transaction. I guess I could have been lied to about the round count. But the shop owner gauged a brand new BCG (DMPS if that makes any difference) and it was fine which is what is throwing me off. The BCM closed but it fit snugly he said.
IIRC it using the .223 and not a real 5.56 gage (Field gage) will give you a false reading. Per the manual when it happens, you are to replace the bolt first and then re-check. If it fails then, you re-barrel, then using the old bolt, re-check again.
In any case I wouldn't expect it to fail so early. As an example- my BCM had well over 5K when I swapped configurations and it easily passed when I checked it with a 5.56 Field gage.
Mr. Gunshop guru should have known this.
blackjack_03
04-26-12, 18:41
Well since he does deal in mainly brands that chamber their rifles in .223 instead of .556 I don't doubt he was using .223 gauges. I didn't see them closely but wish I had now. Glad you brought that up as I hadn't thought of it. I just need to break down and get my own set anyway. Hell if I can afford the rifles whats a few bucks for some gauges.
davidjinks
04-26-12, 18:43
Pure speculation on my part…
I don't think the gun store dude knows what he's doing. Maybe the wrong gauges were used or were used improperly.
You mentioned you had 2 other rifles that failed the gauges but had less than a 1000 rounds through each one. That's kinda weird right there.
Personally, I'd order a good set of gauges, educate myself on them and do it myself, per the manual.
This is my only rifle with using a used part. I'm not sure of the gauging process, he did it in front of me but I didn't get a close look at the gauges he was using. The barrel was bought used in a private transaction. I guess I could have been lied to about the round count. But the shop owner gauged a brand new BCG (DMPS if that makes any difference) and it was fine which is what is throwing me off. The BCM closed but it fit snugly he said.
A real 5.56 headspace gage is difficult to find. In any case most all gunsmiths use Clymer or Forster headspace gages and they are all chambered in .223.
Bushmaster may still sell their 5.56 headspace gage. You will need to remove the extractor to get a reliable reading.
IG, do you know if the Brownell's field gauge is any good? They advertise that it's made to Colt specs. http://www.brownells.com/.aspx/pid=6646/Product/5-56mm-223-HEADSPACE-GAUGE
I believe that it is wrong.
IG, do you know if the Brownell's field gauge is any good? They advertise that it's made to Colt specs. http://www.brownells.com/.aspx/pid=6646/Product/5-56mm-223-HEADSPACE-GAUGE
A real 5.56 headspace gage is difficult to find. In any case most all gunsmiths use Clymer or Forster headspace gages and they are all chambered in .223.
Bushmaster may still sell their 5.56 headspace gage. You will need to remove the extractor to get a reliable reading.
FYI, I looked on fosterproducts.com (http://www.forsterproducts.com/categoryShopping.asp?category=22919&catid=19938) and they do have NATO 5.56 min and max gauges.
The correct gage with rebated rim should be 1.4370. I only use the one called for in the TM.
FYI, I looked on fosterproducts.com (http://www.forsterproducts.com/categoryShopping.asp?category=22919&catid=19938) and they do have NATO 5.56 min and max gauges.
You will not get any better advice, based on experience armoring our troops, than IG. I take his advice as the gold standard, and it has been correct every time. I use to dbl. check with a known master military armorer and he concurred every time. If IG's old ass brain has some memory left(breathing yrs. of gunsmoke can be detrimental:D), he can guess of whom I speak. I'll just say he lives in the NC mtns.
Sounds to me like the dudes gauges are out of whack.
Improper headspace testing can damage gauges. If you have two level one manufactured rifles with low round counts (and the colt barrel) all failing on no-go and field gauges, then, as others have suggested, there's something rotten in the state of Denmark.
I'd guess it's a case of "tolerance stacking", as in he's using commercial (.223) gauges AND he's tested improperly long enough that they are now out of spec.
There's another possibility though. I'm not saying that this is the case, but there's a chance that since this guy makes a living selling shit parts as you stated in the OP, he might have intentionally ****ed up his gauges so he can appear to be testing properly and convincing suckers to buy new shit.
It's always a possibility.
Most 223 gauges are made for gunsmiths. Gunsmiths generally chamber bolt guns at or just above minimum. As a result most 223 NO-GO gauges are nowhere near the SAAMI max, or 5.56 acceptance max.
I would like to see the actual length of the gauge referenced to avoid confusion.
I'd find it hard to believe that a Colt product with relatively low use would be messed up.
No offense, but your guy doesn't seem to be an incredibly reputable source of useful information....
I'd find it hard to believe that a Colt product with relatively low use would be messed up.
No offense, but your guy doesn't seem to be an incredibly reputable source of useful information....
You would be very surprised...
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blackjack_03
04-27-12, 15:46
I only went to him because I don't have a barrel wrench yet so I went ahead and got it headspaced after the barrel was put on. He proceeded to tell me to get rid of my m16 carrier. I almost wonder if he was using a go gauge instead of no-go to try to sell me something.
He saw my BCM bolt and asked if the HP MPI engraving was the brand name and I just got my stuff and left. ALso he did not remove the extractor on anything.
I don't think i will even buy earplugs from this dude.
Would it be recommended to use a field gauge or no-go gauge?
Blankwaffe
04-27-12, 17:49
I only went to him because I don't have a barrel wrench yet so I went ahead and got it headspaced after the barrel was put on. He proceeded to tell me to get rid of my m16 carrier. I almost wonder if he was using a go gauge instead of no-go to try to sell me something.
He saw my BCM bolt and asked if the HP MPI engraving was the brand name and I just got my stuff and left. ALso he did not remove the extractor on anything.
I don't think i will even buy earplugs from this dude.
Would it be recommended to use a field gauge or no-go gauge?
All I use is a USGI Field Reject Gage that Iraqgunz references frequently here.
Before that I was using the Brownells Colt II Field Reject that I had the rim turned down to rebated profile.
Ive not had an AR that would not easlity close(finger pressure on carrier tail like with a gage) on a catridge due to minimum headspace.So I don't have or see the need to use a GO gage.
Depending on quality of components or supplier could increase need for other gages,but I try to avoid said situations.
After some use the bolt and barrel extension lugs will burnish in with wear,so I only worry about reject headspace.
polymorpheous
04-27-12, 18:20
Bushmaster may still sell their 5.56 headspace gage. You will need to remove the extractor to get a reliable reading.
Do you mean the ejector?
I only went to him because I don't have a barrel wrench yet so I went ahead and got it headspaced after the barrel was put on. He proceeded to tell me to get rid of my m16 carrier. I almost wonder if he was using a go gauge instead of no-go to try to sell me something.
He saw my BCM bolt and asked if the HP MPI engraving was the brand name and I just got my stuff and left. ALso he did not remove the extractor on anything.
I don't think i will even buy earplugs from this dude.
Would it be recommended to use a field gauge or no-go gauge?
Ok, keep in mind, im just passing on info I think ive gained here so if someone else corrects me - they are probably correct.
I dont think you need headspaced for that. As I understand it - 99% of barrels you buy have the barrel extension already installed. When you buy a barrel assembly, you just stick it in and torque it to spec with a barrel wrench. Headspace is set by the extension, at the factory, and as I understand, cannot be changed(or its a GIANT pain in the ass).
That said, its not bad to check, but if you buy top quality stuff, the chances of it being jacked are astronomical.
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