AR uppers

[Squirrely]

Anyone here build them. I have a question or two.

 

Mostly, I'm having trouble getting the barrel to seat flush with the upper receiver. What's happening is a slightly canted barrel. So to sight in you have to crank everything to the right.

 

Am I missing a trick here?

[Squirrely]

After some research.

 

I guess I will need to take my upper apart and check for debris. Then when I reassemble, I torque and loosen the barrel nut a few times to help assure that all is seated correct. If I still have problems then something is out of spec.

 

Guess I'll find out in a week

[LOBO]

www.m4carbine.net

[FargoZ71]

Ar15.com is much friendlier. Debris, grease, tq, re tq, ect.. last ditch effort.. check the chamber to make sure its straight with the barrel...

[Squirrely]

I'll probable tear this down this weekend. What a bummer too, I had it all done up nice, lock tight, etc. But if it doesn't shoot straight then it's no good.

 

I found some info on the AR15 site. Looks like I made a rookie mistake.

[hollis092]

I build AR's and perform service and upgrades. Let me know if you need some help - PM me.

 

What was your mistake?

 

When you installed the barrel, was the barrel tit and the groove in the upper aligned? Torque your barrel down enough?

I don't ever use locktite - general rule of thumb - things always need to be taken apart for some reason.

[BlackZ71Silverado]

What brand of parts are you using for this build?

 

 

Sent from my iPhone4S

using Tapatalk

[Squirrely]

sorry, been busy.

 

Rock river upper, Daniel Defense barrel, MI sights and quad rail

[hollis092]

Made any progress - got that thing shooting like it should?

[Squirrely]

All right.

 

Tore it down today and took serious time to reassemble. There were a couple things I noticed that I missed last time. These may seem like common sense but I just figured it out, or so I think

 

The barrel nut has indents in it for the set screw on the quad rail. Once I torqued the nut, loosened and re-torqued 5 or 6 times, I had to take great care in making sure these indents didn't twist the rail once installed with the set screw. Basically I had to thread the quad rail, install the set screw, and check if all was square. If it wasn't then I took the rail off and ever so slightly added a little more torque to the barrel nut until I got everything straight.

 

I think I had everything ever so slightly twisted, and when you add up the distance of the sight from center of the bore, that was probably enough to cant my sights.

 

Hopefully I got it this time.