I have a DD RIS mk 18 rail and it is slightly canted to one side, making 10.5 Noveske barrel off center. I have tried to reseat this rail multiple times to no avail. I have a DD Lit 14 inch rail that mounted straight. Does anyone have any ideas on how to rectify this situation?
The rail alignment block from Brownells helps. Sometimes the gas block is off a few degrees and some times the rail on top of the receiver isn’t square.
I am using a Forged Upper, if I am understanding you correctly, it could be the culprit?
I used a carry handle to align the rail, as I always do.
It could be the upper but if the gun is working and the feed ramps in the barrel extension are aligning well with the upper receiver I wouldn’t sweat it.
It has been short stroking, but I thought the reason is because gas was leaking out of the gas tube pin ( residue was on teh underside of the rail on both sides of the gas block. I haven’t test fired the Rifle since reseating the gas block pin. This rifle has been a real head banger, i haven’t had a single issue with my other builds, yet this one seems plagued. I have found metal shavings when I cleaned it. I really appreciate your input.
Was the gas block drilled/pinned by Noveske?
Some gas bleed off is normal. What ammo were you using and how wet with oil did you have the BCG?
Double check the back side of your locking ring and the barrel nut. It doesn’t take much foreign matter to screw throw off your true when you mount these rails. Do you have access to any other means of aligning the rail? I’ve used ADM mounts to get me in the ballpark and fine trued the rail up by adjusting the screw tension very carefully. You might want to double check the rail too, make sure it doesn’t run out in one direction.
Yes, it was pinned by noveske. the bleed was much greater through the gas tube pin than the minor bleed from around the tube at the block on teh barrrel. The BCG was well lubed.
Also, you may want to back your barrel nut off to see if you have something between the shoulder of the barrel extension and the upper or the barrel nut. I had a Troy barrel nut that just wouldn’t align until I took it apart and wiped everything down very carefully and re-assembled.
What ammo?
Great suggestion, but I have already tried that. It got better but is still off.
Th e most frustrating thing si that I am using the best parts, but it just doesn’t want to come torgether.
55gr ultramax remanufactured, and I tried some factory 55 gr .223 woith tthe same results.
Ultramax is are pretty weak.
I’d try some XM193, M855 or Black Hills ammo and see what happens.
I have taken the upper completely apart, cleaned everything thoroughly, and then reassembled.
That was the BEST money I ever spent!
will do
thanks for yall taking your time
Unsuppressed I’d also recommend a H buffer but nothing heavier.
Just to make sure I’m picturing things correctly, it is the barrel inside of the end of the rail that appears crooked and not the gas block canted to one side, correct? Does the gas key slide over the gas tube without binding? A misalignment there could suggest a canted gas block. Do you have a way of checking the barrel nut to make sure it is square?
If the Lite Rail mounts on straight, on the same upper, sounds like the RIS may be the problem. I had the same problem with an older light rail. DD will take care of you.