Quick AR accuracy test.

[C-grunt]

So there is talk around other shooting forums that BCM makes inaccurate barrels. Not flukes or one offs, but that their entire barrel line is considerably less accurate than their counterparts. People are saying they are 4 MOA guns. This was brought up for discussion on another forum I post on and I decided to do a little accuracy comparison with my ARs vs my rebuilt Colt with a BCM barrel. I thought you guys might enjoy it. Here is the posting:

*****

So I went out this morning with 4 ARs to test for some accuracy.

To be clear this test isn't fair as each rifle had different sights. Also the red target used for most of the test does not do well with my eyes and non magnified optics. Plus having an astigmatism in my right eye, red dot optics are not crisp even with glasses or contacts. So those are my excuses. HAHAHA

Testing was done at 50 yards using bags and a bench. It was 68 degrees and sunny. Wind was light to moderate and moved the target somewhat. I tried to wait until wind gusts died down between shots but it is possible the wind affected the groups slightly. Ammo used was American Eagle 55 grain except for the groups on the black ring target which was 55 grain Geco.

Pic of the shooting setup.

20200301_115220 by chase ditwiler, on Flickr

First up is my duty rifle Colt 6920. It has a RAS rail, stock trigger, and a Steiner P4Xi scope. Rifle has around 13k rounds through it and Ive been carrying it for 10 years.

20200301_114618 by chase ditwiler, on Flickr

Group at 50 yards.

20200301_140051 by chase ditwiler, on Flickr

Next was a rebuilt Colt 6920. Barrel is a BCM ELW middy in a Geissele Mk2 rail. Rifle has a Sionics upgraded trigger and it using a Trijicon MRO optic. That barrel has about 3500 rounds through it.

20200301_114621 by chase ditwiler, on Flickr

Groups at 50 yards. I switched to the black ring target which was much easier to get a consistent point of aim.

Screenshot_20200301-135804_Range Buddy by chase ditwiler, on Flickr

20200301_140019 by chase ditwiler, on Flickr

20200301_135956 by chase ditwiler, on Flickr

Next rifle is a franken build using a FN 20 inch barrel, RAS rail, Colt carry handle, and milspec type trigger.

20200301_114626 by chase ditwiler, on Flickr

Group at 50 yards. I used the small aperture and it's set for 300 yards.

20200301_140035 by chase ditwiler, on Flickr

Last is a franken build pistol. Barrel is a Ballistic Advantage 11.5 government profile. Rail is a Odin Works. Milspec style trigger.

20200301_114623 by chase ditwiler, on Flickr

Groups at 50 yards. Again switched to the black ring target. As you can see one of the groups was much better than the other. The unmeasured group is a bit larger than usual and the measured group is a bit smaller than usual. This pistol usually averages about 2-2.5 MOA with American Eagle and the Geco.

20200301_135936 by chase ditwiler, on Flickr

20200301_122436 by chase ditwiler, on Flickr

 

[taliv]

Are they claiming that is a recent phenomenon or that bcm has been making bad barrels for 15 years and someone just noticed?

I’m trying to remember but I don’t think I have any bcm barrels. I never liked their profiles.

 

[earlthegoat2]

Buffalo Outdoors channel has similar testing with BCA 450 BM and 458 SOCOM uppers.

Found they are also pretty accurate.

 

[C-grunt]

Are they claiming that is a recent phenomenon or that bcm has been making bad barrels for 15 years and someone just noticed?

I’m trying to remember but I don’t think I have any bcm barrels. I never liked their profiles.

I know about 5 years ago people were complaining that the BCM SS410 stainless barrels weren't as accurate as others. My SS410 is a solid .75-1 MOA gun with good match ammo and shoots decent 55 grain bulk ammo at 1.75 MOA regularly. My friends Rainier Super Match is closer to a 1/2 MOA barrel with good ammo.. I always believed that BCM might make their chambers a little more generous in their stainless barrels to keep reliability high at the expense of a little accuracy loss. Just my hunch though.

Ive never heard people complain about their "regular" barrel line until this last week. For me this BCM ELW barrel shoots slightly less accurately than the Colt barrel it replaced when using bulk ammo. But I attribute that to my Colt barrel shooting well for a chrome lined non match grade barrel, than the BCM barrel being subpar.

 

[gotboostvr]

With tuned in handloads my 16" SS410 shot phenomenally.

 

[cougar1717]

Great testing!
At the end of the day - accuracy depends on many factors. It's great to try to keep the ammo as even as possible with AE 55gr and Geco 55gr. If you tested again with XM193, the results may be different. Or if you compared tuned handloads for each rifle.
I've seen AR's that are nothing special with the typical, inconsistent 55gr FMJBT. However, give that same rifle a Vmax or NBT, and now it's at or below 1 moa. There are also rifles that shoot 1.5 moa with irons so you get a scope on it to see what it can really do... only to find out that it shoots 1.5 moa with a scope too - haha.

It's always difficult to compare apples to oranges, especially when the sighting systems are different. It would be interesting to see what would happen if the scope was moved from rifle to rifle to even out that aspect.