BenL
John Galt Speaking.
I'm installing a barrel and have tried two different barrel nuts. The gas tube doesn't line up at 30 ft/lbs and even at 80 ft/lbs, it still doesn't quite line up. Can I go up to 90 ft/lbs, or do I have to use shims?
Try torqueing and releasing and torqueing and releasing.
I've been able to gain that little extra bit of rotation by doing this 5 or 6 or more times.
If you haven't done so, lube the hell out of every load bearing point each time prior to retorqueing.
JMOOO
Beyond shearing the Barrel Nut or Upper Receiver Threads, its possible to twist the Upper which will result in not being able to get on paper or getting the Upper on a Lower. It usually take much more than 80ft/lbs to do that damage though. over 100 will usually be the starting point.
It either causes the barrel timing pin to widen the notch in the Upper which will cause the Barrel to not index properly or cause misfeeds due to the ramps, or depending on how the upper is secured it can twist the rail on the Upper.
I have seen many twisted AR uppers
What barrel nut? Factory?
Try torqueing and releasing and torqueing and releasing.
I've been able to gain that little extra bit of rotation by doing this 5 or 6 or more times.
If you haven't done so, lube the hell out of every load bearing point each time prior to retorqueing.
JMOOO
What nut/rail system??
What kind of barrel nut? Can you just take a lug off the nut with a dremel to allow clearance for the gas tube? I did this on a pistol build, works fine..
Okay, understand... when the nut is properly indexed for the rail is there a tooth on the standard barrel nut that interferes with the gas tube?The Fortis REV rail relies on the 3 and 9 o'clock lugs to maintain it's timing. If they're not lined up properly, the forerail will be off timing. If I were using a Noveske forerail, I could get away with that because its proprietary nut's timing doesn't effect the gas tube alignment. Plus, I'd rather it be done properly. It would bug me, otherwise.
I have the same issues with MI barrel nuts. If the teeth are warped you shod replace the nut.
I often lap the upper receiver face and this helps sometimes.
I say order a new nut and some Barrel shims. Try the torque and loosen technique and only use the shims if necessary.
I have the same issues with MI barrel nuts. If the teeth are warped you shod replace the nut.
I often lap the upper receiver face and this helps sometimes.
I say order a new nut and some Barrel shims. Try the torque and loosen technique and only use the shims if necessary.