This is a basic accuracy test on a RRA barrel 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.
This is a 556
chambered, midlength, lightweight, chrome lined, 1/9 twist, home
assembled upper. This barrel is a bit thicker in profile than a "pencil" barrel
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. The lower is a
Stag with a DPMS LPK and a CavArms A1 stock.
As tested:
I intended to shoot 10-shot groups for this test, 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. Shots were measured with dial calipers using the extreme spread technique.
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:
interesting to note that the heavier loads shoot to a lower point of aim
Note that the 75 grain ammo shot fine in this 1/9 twist barrel. People say 1/9 won't stabilize bullets above 70 grain. But sometimes it works, and it did here.
I was really impressed with the Hornady Steel match ammo, that's the best I've ever seen it group.
This is in no way a precision rig, I just wanted to see how it would shoot. I'm very happy. Thanks RRA!