I am no PhD in gun building. I am building a Noveske 7.5 upper and I am having the hardest time getting the barrel nut torqued into the right position for proper NSR rail alignment. I have literally fiddled with this for a few hours.:mad: I’ve tried installing barrel nut both ways and every time I torque it down, I’m off about 1/8-3/16 inch and I cant get the anti rotation pin in both upper and rail. I even tried shims, but I am left with a little more gap than I prefer. Is the torque requirements for the NSR barrel nut a " LAW" or do I have a little flexibility? I can torque the nut to about 75-80% and get the right timing but is that safe?
The NSR nut has more timed positions than a stock barrel nut, so it should be easier. Because it has to be timed you will have trouble using an exact torque value, though.
I have installed a few of them. I torque the nut to 40 ft lbs and then loosen it three times in a row, paying attention to how close the timing is. Then I set the wrench to 80 ft lbs and do the final torque. As long as it times above 40 and below 80, you’re good.
There are a lot of advocates for keeping the torque on the low end of the scale for supposed accuracy gains, but it’s tough to do this with a barrel nut that has to be timed unless you’re willing to use shims or cut the face of the receiver.
OP what are you using for grease on the threads? In the past I’ve noticed a few % difference between say moly grease and high temp anti-seize. Same with how much the barrel nut would index.
What torque value are you getting on the low end with the barrel nut properly timed? What about the high end?
It took a while for mine to time properly. A lot of tightening and loosening. And yes, definitely use grease on the threads.
Had the same issue with mine. Solve with more liberal grease on threads (upper & NSR) and torque. I was at it for hours and I just stopped, reread the instructions, regreased and it went together between 80-90ft-lbs. Cannot explain except a lack of lubrication issue. Seems like the grease helps the NSR rotate more with each torque value, but just my thoughts, an engineer can chime in.
Similar issue with gas block pin on my Noveske barrel, complete PIA and impossible to install, but if you oil the pin, pop it in the freezer for 1/2 day goes in like butter.
Agree with above. I’ve installed three…one of them went down with about 60 ft-lb, the others took lots of grease and every bit of 80 ft-lb to get timed. NSR is not my favorite handguard. It was great in its time though.
After building with a couple NSRs, I’ve decided to only use rails with barrel nuts that do not need to be timed in the future.
That being said, put moly grease, do it 3 times to 40 ft lbs, then go from 40 to 80 ft lbs, stopping at any point between the two if it lines up.
Amen, the BCM KMR is a great keymod rail choice (other out there as well) with a much easier painless install. FWIW, the NSR was my choice for a first build and I regretted it as I didn’t understand “timing” in practice…had only read the instructions.
I love my NSR but had the same problem. Mine took finally at 72#
My install coincided with the release of the KMR. Totally would’ve gone that route.
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I tried to get the torque right about 25 different times. I kept needing to go past 90lbs to get close. I tried reversing the nut and it didn’t matter. I ended up with about 32lbs of torque on the nut. I wasn’t pleased. I sold the raid and went bcm before I could see how the rail held up.
Agree. No reason to get rid on the one rifle I have with an NSR, but I definitely prefer the KMR I have on the other, both from a functionality and an install standpoint. NSR ain’t nothin’ special anymore.
thanks everyone, after about 200 attempts, I finally got that bastard son of a bitch on- excuse my language! I invented a new tool, perhaps the easiest way to do this. put the NSR nut on and tightened to 75# then attached NSR rain and finished tightening to 90#-perfect alignment-after 4 -5 attempts, unscrewed rail, inserted anti rotation pin, and reassemble. Gun is still unfinished but here is a photo of the rail assembled to reciever
I’ve read some people use a receiver lapping tool to assist with barrel nut timing. I’ll be installing my NSR next weekend - guess i’ll see for myself
Good luck… be patient!
This rail makes me want to kick baby lions. I have only installed around 6 of them, but they were all a pita. Plus having to get that stupid crows foot wrench head. I did like I usually do. I simply ignored the torque, worked the nut a few times and got it lined up, and went from there. All of the build I did with the exception of one had the upper with the indexing/anti-rotation hole. If I was doing KeyMod, I would stay with the KMR.
On the 1 that I installed I think i went to 90 or even 95 and I probably did 20 torque sequences to attempt to stop at 80 and I use the aeroshell 33ms grease. nothing between 40 and 80 were near lined up ever. I knew the guy I was building for would NEVER take the thing apart so the high torque and chance of damaging the receiver threads didnt bother me. As far as accuracy the thing is an absolute tack driver so I tend to not buy into the “less torque is better” way of thinking.
If I could do it all over again, I would have waited for the KMR. I couldn’t get alignment using torque values, I did exactly what you described to attain alignment.
Wish the KmR would come out in MLok…
Don’t hold your breath.