Author Topic: Colt AR-15 lower (Read 461 times)

dharris · « **on:** August 25, 2003, 05:22:39 PM »

I have a preban Colt lower that causes the uppers I have installed shoot to the right. I have tried three uppers of different barrel lengths, etc., and the rifle shoots right. All appears to be OK with the eyeball inspection. Any ideas? Thanks.

John Traveler · « **Reply #1 on:** August 25, 2003, 05:36:22 PM »

1. How far to the right does it shoot?

at 25 yards?
at 50 yards?
at 100 yards?

2. Are you comparing point of impact to the same barrels installed on another AR-15 lower?

3. Are the barrels attached to the lower using the correct diameter pin, an eccentric adapter pin, or an undersized pin?

Try using an "Accuwedge" to tighten up the upper/lower receiver assembly. A thin, common piece of hard rubber in the receiver hinge area will work.

dharris · « **Reply #2 on:** August 25, 2003, 05:56:14 PM »

The rifle shoots "way right." About 14 to 16 inches at 100 yards with centered iron sights, or optically centered scopes. I realize some adjustment is necessary, but it really bugs me when I have to crank the sights/scope so far to the left. I have the following uppers: a standard A2, a heavy varmint, and a CAR. I have tried a few different front/rear pins and have always used the accurizing wedge. I am beginning to believe the lower was cast "crooked" or is bent.
Thanks for the advice. Dharris

gunnut69 · « **Reply #3 on:** August 25, 2003, 08:38:32 PM »

Do these uppers shoot to point of aim when mounted on other lowers? Perhaps the problem isn't with the lower... I suppose there may be some way the lower could force an upper to shoot one way or another but I don't know what it would be.. The complete barrel bolt assembly is in the upper.. I can thenk of things there that could effect the rifle's point of impact, but I'm blank where the lower is concerned. Try those uppers on someone elses lower, and see where the shoot.