Quoted:
I went shooting today and thought I'd share my results with you. I took my 12 year old son and he pounded away at imaginary Redcoats with his 10/22, but that's a side story.

I went with the intention of doing a basic accuracy test on two new uppers using factory and reloaded ammo at 100 yards, with a SS 10x mildot scope in an ADM mount.  Weather was 85 degrees, threatening rain, and breezy/gusty wind.  Shooting bench was arranged as shown here in a previous test with a different rifle.

First up, a BCM 16" 556 chambered, midlength, lightweight, chrome lined and hammer forged barrel, 1/7 twist, factory assembled upper. This was purchased a few months ago and other than a rough sight-in at an indoor range is has not been shot.  It can be seen on BCM's website here. The lower is a Stag with a DPMS LPK, nothing fancy.

Here's the test bed:

http://i1011.photobucket.com/albums/af236/onehalfmvsquared/hobby/IMG_0675_zps18108a12.jpg

The groups were all 10-shot save for the one noted, and measured with a dial caliper using the extreme spread technique.  I waited about 15 seconds between shots, which is probably too fast.

1.305  -handloaded Sierra 52 gr HPBT (1 called flyer - wind blew a box off the bench and I flinched)
1.630  -handloaded Hornady 55 gr FMJBT
2.128  -Federal 55 gr FMJ "Wal-Mart black box"
2.137  -Hornady 55 gr Steel Match
2.430  -Federal 62 gr Fusion MSR  bonded soft point
2.630  -Hornady 75 gr Steel Match (5-shot only, all I had left)
4.066  -Winchester 64 gr Power Point Jacketed Soft Point

Edit: I did the calculations for Mean Radius on a few of these

0.461 -handloaded Sierra 52 gr HPBT
0.553  -handloaded Hornady 55 gr FMJBT
0.857  -Federal 55 gr FMJ "Wal-Mart black box"
0.667  -Hornady 55 gr Steel Match

Note that the Federal 55 has a smaller ES, but the Hornady 55 Steel Match shot a tighter group (MR)


Here's a shot of the Sierra handload and the Federal FMJ

http://i1011.photobucket.com/albums/af236/onehalfmvsquared/hobby/IMG_0681_zps901de648.jpg



The second is an RRA 16" 556 chambered, midlength, lightweight, chrome lined, 1/9 twist, home assembled upper. This barrel is a bit thicker in profile than the BCM and has a 0.750 gas block, but does not have M4 feedramps.  It was one of the first "lightweight" profiled 16" midlengths offered by any company and I bought it as a barrel assembly. It can be seen here part number AR0213CLASY. I assembled it onto a generic upper without ramps last week. I used the same optic as with the BCM. The lower is a Stag with a DPMS LPK as well, with a CavArms A1 stock.

As tested:

http://i1011.photobucket.com/albums/af236/onehalfmvsquared/hobby/IMG_0653_zpsd7c451a5.jpg

I intended to shoot 10-shot groups for this test too, but the RO said that he was closing up an hour earlier than normal, so I had 15 minutes to shoot all of these.  I decided to go with 5-round groups and shot them very rapidly.

0.820  -Hornady 55 gr Steel Match
0.833  -Hornady 75 gr Steel Match
1.302  -Handloaded Sierra 52 gr HPBT
1.360  -Federal 62 gr Fusion MSR  bonded soft point
2.228  -Handloaded Hornady 55 gr FMJBT
3.233  -Winchester 64 gr Power Point Jacketed Soft Point

The top three:

http://i1011.photobucket.com/albums/af236/onehalfmvsquared/hobby/IMG_0654_zpsab63e70f.jpg

Thoughts:

Both uppers are more defensive-type than precision rifles, but I wanted to see how they would do.  I'm happy with how they did.

The RRA 1/9 twist barrel seemed to shoot the heavier bullets better, opposite of what I expected.  I wonder if the BCM barrel had gotten too hot by the time I shot the heavy loads.  I'll go back later and test the heavier loads more slowly from a cold barrel.

Note that the 1/9 twist barrel shot the 75 grain bullet just fine, better than the 1/7 twist barrel.

I expected a bit better from the BCM overall given my previous experience with the 20" govt barrel using the same ammo. I did not intend to buy the BFH (hammer forged) barrel, but the standard one.  But the upper was bought during the recent panic and when it became momentarily available online and I did not check the description close enough when ordering.  I wonder of the hammer forged barrel is not as accurate as the standard one, or if it needs more of a break-in period.

Perhaps this is not a proper comparison between the two barrels because one is 10-shot and the other is 5.

Winchester Power Point SUCKS and has ALWAYS sucked for me.  I've shot factory loads and handloads through several different barrels of various twists and it always does the worst of all the ammo tested.  The 3.233" group is actually the best I've ever seen.  I've had groups as large as 5-6 inches at 100 yards.  It's on the recommended defensive ammo list, but I've never been happy with it, despite really wanting to be. It gets great reviews on Midway, go figure. If I could get it to do 2.5" at 100 yards  I'd be happy

I was really impressed with the RRA  and the Hornady Steel Match ammo, especially since I was shooting so rapidly.

It's the Independence Day Holiday.  You should take your kids, spouse, SO, or a friend and go shoot.