This was the first time shooting my RRA 16" at distance.  Went to a friends property and was able to get to 75 yds as the 100 yd position was swampy...anyway...

First group was 2 rounds close within 3" and the third was WAY high...like 8".  Second group the same thing, but the flier was closer this time about 6"-ish away from group.  Each three round group the flier distance was reduced.  Strange.

The final couple groups of three and five rounds I really concentrated and took my time and was placing them in 2-3" groups with irons.  I'm pleased with that while laying on the VERY uneven ground and all the 'skitoes attacking en mass.

Total rounds fired was around 50-60 rounds, all 100% function.  All shots with Winchester 55gr FMJ.

Anyone had this happen with a new rifle?  Was it "breaking in"?

Thanks for any responses.

Cheers!

It’s not uncommon for the first round loaded out of the mag to be a flyer.  As the upper mates, this is less common, but still if the idea is to shoot for groups, put the first round in the dirt, and use the second round that is self loaded threw the rifle cycle as the start of the group.

Now on a new button rifled barrel that has not been hand lapped, the barrel will take a few hundred rounds to start to unify it.  This includes knocking down any burs at both the throat and muzzle, unifying the lands and grooves of the rifling, and allowing the barrel to tension unify (stress applied by the button during rifling).

When shooting groups, a 5 to 10 round count is more ideal.  Since you are dealing with a auto loader that feeds from two different sides of the mag, and down two different barrel extension feed ramps, the third round flyer may have been caused by a bur in the mag or feed ramp (only caused when the rifle self loaded, and not the initial loading/charging. By shooting a longer string, this gives a better idea on what the rifle/ barrel is doing, and how it deals with fouling (both powder and copper down the bore).

As for the groups starting high, then lowering over time, this could be due to the barrel tension/ barrel installation in the upper settling in threw live fire.

To sum it up, if you were a DCM master shooter, and where having these problems, then we would just blame the rifle.  But since it sounds like this is one of your first rodeos with the rifle (type), we are less likely to blame the bad ride on the bull. Looks like its time to cowboy it up, and spend your time putting hundreds of rounds down the bore getting your technique correct before you start riding for points.

Thanks for the mechanical anaysis!  Sounds like what was happening.  No, this is not my first go around with ARs.  I'll save everyone from the Blah Blah Blah of my training and experience.  Suffice it to say, I've sent more than the avg amount of rounds down range.  But they were typically with a bolt, or a broken in AR.  Thats the kind of info I was hoping to find.


Anyway, thanks!

Cheers!