Colt AR15 rear sight problem

[Iron Sights]

I went to the range this past weekend with a guy that owns an older second hand Colt AR15. The rear sight was adjusted almost to the maximum right position. It shot nice 50 yard groups for both of us however they were all off to the left of point of aim by about 4 inches. The carry handle did not seem to be removable and overall alignment looked ok.

I'm wondering if someone previously took the rear sight apart for some reason. I looked on the internet and taking the rear sight apart looks like a disaster waiting to happen with the possibility of losing small springs and ball bearings. Has anyone taken a rear sight apart and if so can an adjustment be made when apart to remedy the problem?

Anyone have suggestions on getting the rifle to shoot better? Adding a scope does not seem to be an option since the rifle does not have rails and as I mentioned earlier the carry handle does not seem to be removable. I don't have the rifle in front of me, since it's not mine, so the carry handle comment is from memory.

[QuackXP]

Are you sure the front sight is aligned properly and not pushed to one side?

[Iron Sights]

Are you sure the front sight is aligned properly and not pushed to one side?

The front sight seemed to be aligned with everything else. I believe it is also part of the barrel. Nothing looks like it was damaged on the rifle.

[QuackXP]

The front sight seemed to be aligned with everything else. I believe it is also part of the barrel. Nothing looks like it was damaged on the rifle.

I knew someone who had a similar problem. Although not to the degree you seem to have. He had a mid length gas system. But the standard front sight was at rifle length in a "dissipator" setup. It was never aligned properly although it was tough to tell from just looking at it.

I've taken them apart and its not that difficult. If you can build a lower you can get an A2 rear apart.

[dkf]

http://www.thenewrifleman.com/instal...-visual-guide/

If the rear sight is assembled properly the next best bet would be a canted front sight base.(held on with taper pins)

[Bang]

Look for bent barrel. Look for a dent in the crown. I assume it has an "F" front sight (should actually have an F stamped in it). Check it for vertical. Check that the gas tube does not touch while passing through the nut. Ascertain the twist rate...may have an early barrel with incompatible twist rate such as 1 in 12.

[pennlineman]

I've seen this before on M-16's. At times there is some slop with the barrel index pin and where it mates with the upper receiver. The barrel is leaning right as you look at it from the butt end, not the front sight. Take the gas tube off, loosen the barrel nut push the barrel to left. You'll feel or here it pop ever so lightly. Retighten the barrel nut, install gas tube and you'll be GTG.

[Iron Sights]

Thanks for all the information. I'll have to look at it closer when I have time tonight.

[Bang]

slop with the barrel index pin and where it mates with the upper receiver

Good info. Good suggestion. And, in my case, good teaching!

[Hawk]

I've seen this before on M-16's. At times there is some slop with the barrel index pin and where it mates with the upper receiver. The barrel is leaning right as you look at it from the butt end, not the front sight. Take the gas tube off, loosen the barrel nut push the barrel to left. You'll feel or here it pop ever so lightly. Retighten the barrel nut, install gas tube and you'll be GTG.

^this!