Interesting results after grouping my standard and BFH BCM barrels - update 02 JUN

[AndyLate]

I would suggest focusing on Federal GMM, Black Hills, or Lapua for serious accuracy testing with factory ammo. I have also had good results with Norma and Nosler ammo in .308, FWIW.

Norma TAC-223 55 gr fmj has shot very well for me (shockingly well in one AR).

Andy

[Wake27]

I had some FGMM 77 gr on hand, as well as the CBC and IMI 262 clones, and finally the FGMM with 73 gr Berger bullet. A second hour would’ve been very nice, but I just didn’t have the time unfortunately.

Interesting note about the chrono, there was some wind that day but I never heard it discussed with the class so assumed it wasn’t strong enough to be relevant. There were a few things they didn’t cover though so that may be a bad assumption.

Tracking that 2 MOA is well within spec, that’s why I said I can’t blame BCM if they dismiss it. The PPU was bought sometime within the six months before or after Sandy Hook, so it very well may have not been their most consistent loading. Unfortunately the closest range that I know of that goes beyond 100 yards is about three hours away. Not sure when I’d get the chance to head down there, and I’d probably want higher magnification for that distance.


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[Caduceus]

I don't know if it's feasible at your range but if I have it to myself, I've been known to shoot from the parking lot to squeeze an extra 20-30 yards out.

Safety first and all that.

[Wake27]

I don't know if it's feasible at your range but if I have it to myself, I've been known to shoot from the parking lot to squeeze an extra 20-30 yards out.

Safety first and all that.

It wouldn’t be, unfortunately.

BCM just got back to me with an interesting response. They want me to shoot more groups, discounting the first and last shots, and use either Hornady, Black Hills, Winchester White Box, or “other known good, domestically produced, factory new, brass cased ammo.”

I’ve never heard of discounting the first and last round, and I don’t have glass with enough magnification to do that at 100m. Also kind of seems like cheating. And 3/5 targets I sent them were either Federal GMM or Hornady Black. Apparently that’s not enough of a sample size?

I guess it’s better than them telling me to **** off, but at this point, I’m not sure it’s worth it since only counting the middle three rounds will probably yield a significantly smaller group, enabling the claim that it shoots great.


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[georgeib]

Borrow a scope. And then shoot 7 round groups, discounting the first and last shots...

[gaijin]

I had a new, 16” 300 Blk upper from BCM.
It shot 5”/6” groups at 100 and was iffy keeping rds on a full size IPSC steel at 200.
I contacted them and after brief discussion and with my insistence, they said to send it back.
Their results mirrored mine and they sent a replacement barrel in my original upper, which shoots adequately.

The point; I am certain that all gun manufacturers deal with an agonizingly large number of limp dicks that have no clue what a reasonable expectation is, or actually know their way around a firearm.
You are not included in this group Wake.

I suggest you contact them and STRONGLY insist they send a return authorization so that they can sort this out for themselves.
My experience was that BCM was even handed and did “the right thing”.

[Wake27]

I had a new, 16” 300 Blk upper from BCM.
It shot 5”/6” groups at 100 and was iffy keeping rds on a full size IPSC steel at 200.
I contacted them and after brief discussion and with my insistence, they said to send it back.
Their results mirrored mine and they sent a replacement barrel in my original upper, which shoots adequately.

The point; I am certain that all gun manufacturers deal with an agonizingly large number of limp dicks that have no clue what a reasonable expectation is, or actually know their way around a firearm.
You are not included in this group Wake.

I suggest you contact them and STRONGLY insist they send a return authorization so that they can sort this out for themselves.
My experience was that BCM was even handed and did “the right thing”.

The only reason I didn't respond to that email and insist that they take a look is because I don't have proof of it shooting terribly. I knew I should have taken a picture of the target that the instructor fired but I didn't, so I don't really have anything great to show them. I'm not confident in it, and 2 MOA is not where I want it, but all of the relatively controlled testing seems to result in acceptable results. That's part of why I posted here, I'm trying to see if I'm off base.

[SomeOtherGuy]

BCM just got back to me with an interesting response. They want me to shoot more groups, discounting the first and last shots, and use either Hornady, Black Hills, Winchester White Box, or “other known good, domestically produced, factory new, brass cased ammo.”

I’ve never heard of discounting the first and last round, and I don’t have glass with enough magnification to do that at 100m. Also kind of seems like cheating. And 3/5 targets I sent them were either Federal GMM or Hornady Black. Apparently that’s not enough of a sample size?

I guess it’s better than them telling me to **** off, but at this point, I’m not sure it’s worth it since only counting the middle three rounds will probably yield a significantly smaller group, enabling the claim that it shoots great.

Your 1-6x Razor is plenty magnification for shooting groups at 100M. Some of the best shooting I've ever done at 600 yards was with a 12x scope - roughly equivalent to using your 6x at 300 yards. Off a bench, with decent conditions, 6x is enough to find out how it's shooting at 100 or even 200 yards. Use a front benchrest or good bipod, use a rear bag, go slow. Take a few minutes' break between groups to minimize any effect of barrel heat.

I would load 7 as already suggested and use only the middle 5 for the group, aiming the first and last elsewhere. Although I haven't had an issue with my ARs noticeably throwing the first or last shots, it's conceivable given that the first shot is loaded differently (especially if someone rides the bolt, which is common, even if you don't do it) and potential reaction to the last shot bolt catch. While I don't think this is needed for a good shooter, I don't think BCM is off base given that they don't know you.

If you get repeated 2 MOA groups with these conditions then I think the barrel is meeting expectations. If you can't reliably get under 3 MOA with match ammo, then I think a return to BCM is in order. Accuracy with non-match ammo isn't that relevant because some of the blasting or milsurp ammo will do 3-4 MOA (or worse) in even the best precision barrels. Keep in mind that BCM offers heavy profile SS barrels for a reason, and their ELW is only claimed to be good for what it is, not a benchrest barrel. It's slightly thicker than a pencil, chrome lined, 5.56 NATO chamber (which for BCM likely means a true, somewhat loose, NATO chamber), etc. This is your barrel, right?

https://www.bravocompanyusa.com/BCM-....5-elw-bfh.htm

I have some 16" barrels that shoot much better than this, but they are 50-75% heavier, have .223 Wylde chambers, and are nitride treated or bare SS instead of chrome lined.

One question - do you know if the barrel nut tightening for this upper was in the normal range of torque, and if there were any issues like trouble timing the nut, or loose, or excessively tight, fit of the receiver extension into the receiver? I note that you said Robb Jensen built the upper and I assume he is highly skilled at building uppers, but did he mention any issues like these?

[vicious_cb]

The results are not surprising given the barrel profile. Look at Molon's test of a Gov't Profile BCM BFH using handloads for comparison.

Three, 10-shot groups were fired in a row from the Bravo Company 14.5” barrel from a distance of 100 yards with the resulting extreme spreads:

1.58”
1.96”
1.50”

for an average 10-shot group extreme spread of 1.68”. The three, 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius of the 30-shot composite group was 0.49”
The smallest 10-shot group . . .

https://www.ar15.com/forums/ar-15/Ac..._/118-687913/?

[Wake27]

Your 1-6x Razor is plenty magnification for shooting groups at 100M. Some of the best shooting I've ever done at 600 yards was with a 12x scope - roughly equivalent to using your 6x at 300 yards. Off a bench, with decent conditions, 6x is enough to find out how it's shooting at 100 or even 200 yards. Use a front benchrest or good bipod, use a rear bag, go slow. Take a few minutes' break between groups to minimize any effect of barrel heat.

I would load 7 as already suggested and use only the middle 5 for the group, aiming the first and last elsewhere. Although I haven't had an issue with my ARs noticeably throwing the first or last shots, it's conceivable given that the first shot is loaded differently (especially if someone rides the bolt, which is common, even if you don't do it) and potential reaction to the last shot bolt catch. While I don't think this is needed for a good shooter, I don't think BCM is off base given that they don't know you.

If you get repeated 2 MOA groups with these conditions then I think the barrel is meeting expectations. If you can't reliably get under 3 MOA with match ammo, then I think a return to BCM is in order. Accuracy with non-match ammo isn't that relevant because some of the blasting or milsurp ammo will do 3-4 MOA (or worse) in even the best precision barrels. Keep in mind that BCM offers heavy profile SS barrels for a reason, and their ELW is only claimed to be good for what it is, not a benchrest barrel. It's slightly thicker than a pencil, chrome lined, 5.56 NATO chamber (which for BCM likely means a true, somewhat loose, NATO chamber), etc. This is your barrel, right?

https://www.bravocompanyusa.com/BCM-....5-elw-bfh.htm

I have some 16" barrels that shoot much better than this, but they are 50-75% heavier, have .223 Wylde chambers, and are nitride treated or bare SS instead of chrome lined.

One question - do you know if the barrel nut tightening for this upper was in the normal range of torque, and if there were any issues like trouble timing the nut, or loose, or excessively tight, fit of the receiver extension into the receiver? I note that you said Robb Jensen built the upper and I assume he is highly skilled at building uppers, but did he mention any issues like these?

The magnification at 100m was in reference to being able to see the first and last shots so that I could ignore them, though if I aim those elsewhere like you suggested, that becomes a non-issue. He didn’t mention anything about the barrel nut. I have wondered about it since it was mentioned before and the MK16 was rumored to have some issues with it, but again, I’m assuming that there were no issues with the install. For all of the lowers I’ve built, I’ve yet to mess with an installed rail, but maybe I’ll throw it in the vice to see if I can figure that one out.

The results are not surprising given the barrel profile. Look at Molon's test of a Gov't Profile BCM BFH using handloads for comparison.



https://www.ar15.com/forums/ar-15/Ac..._/118-687913/?

Yeah I did look at his posts for comparison. The fact that those were 10 shot groups lead me to believe that they’d be somewhere between 1/8-1/4 of an inch larger than a five shot group. I don’t know how true that is, but if it’s a close estimate, it would tighten them up decently. If that’s the difference between ELW and Gov’t profile, then so be it, I like the little bit of weight savings out front. However, my backup non-BFH gun with the ELW-F barrel seemed to indicate that the accuracy could be just as good as with the gov’t profile. I wish I had another of each barrel to test for a better sample size.



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