Zebra644 Posted March 2, 2014 Report Share Posted March 2, 2014 (edited) Ok, now its my turn for some advice lol. So I decided to give my work rifle a face lift/work over. Its a Spikes Tactical with a brand new Gen 2 Billet upper / same old Forged lower / BCG, NM 2 stage trigger, Magpul UBR, and AFG, Aimpoint Pro, Troy flips, new claymore brake, Noveske NSR 15 inch rail, Odin mag extension, Magpul BAD lever, Magpul /Novekse ambi saftey, a 16" Daniel Denfense CHF 1:7 twist barreland Surefire X300 ultra with tape switch. So the new stuff is the upper, the Noeske NSR rail, and Troy Claymore muzzle brake. I had the smith at the gun store put on my rail. He stated that 35 lbs of tourqe was enough so that the Novske barrel nut would line up for the keymod rail screws to attatch to the barrel nut. I mentioned something about the directions stating to 65-80 lbs of torque he said 35 was fine, ok, I've not been to an armorer school yet so I am not gonna argue. So I put the the Troy on the muzzle and made sure the upper was attached to a Pather Claw in a vice then off to the range. I zero mine in at 25 yds since this is a CQB type gun and not likely I'll be shooting past 50 yds 100 tops, and to eliminate aiming high at shorter distances to compensate for the distance from front sight to bore. So I am using 55 gr PMC which shoots 4 shot groups allmost one hole out of this gun. I am sitting at a bench with my wedge sandbags and shoot my first group, it is way left, so I adjust my sights to the point where it appears the the rear sight is going to over index/bottom out to the right, I AM PISSED. I take a break, I remove the NSR rail, double check everything, reattatch the rail and go back at it. So now its shooting way right. I think ok, maybe oneside got screwed way too tight or the rail was some how off center and I fixed it. I start to adjust my sights a few clicks and now it shoots way left again,I re-adjust then it goes way right. Finally on the last strig my group opened up from bugholes to the size of a tennis ball. I grab the rifle to sit it down and start counting as I am madder than hell. Then I notice the rail will rotate coounter clockwise about 1/4 a turn, the barrel is now loose and I went ashen. I call up another FFL guy I buy stuff from and he also builds rifles. I take a well needed drive he removed the rail and I unscrewed the barrel nut by hand. We checked out the upper and miked the threads and U shaped notch to make sure the barrel index pin didn't fubar the upper. He listened and read the instructions, it took close to the 80 lbs of torque to get it lined up. We double checked the rail by mounting my Aimpoint forward enough to have the mount to rest on both the rail.The upper reciever and the holes lined up for the NSR mounting srews to thread into the barrel nut. SO after all the above info, was the under tourqued barrel nut the cause of my problems with the groups going both ways and almost bottoming out my rear sight on windage? Will re-tourquing the barrel nut to the propper specs as it is now solve my problem? What else have I overlooked? :help: Edited March 2, 2014 by Zebra644 Quote Link to comment Share on other sites More sharing options...
texas30cal Posted March 2, 2014 Report Share Posted March 2, 2014 ANYTIME I torque something I lube the threads and the shoulder it tightens against that way you are not fighting friction when tightening. I have seen some loctited but do not recommend that. Quote Link to comment Share on other sites More sharing options...
Zebra644 Posted March 2, 2014 Author Report Share Posted March 2, 2014 The barrel nut was lubed as per the instructions with a grease from JP Enterprises. Quote Link to comment Share on other sites More sharing options...
unforgiven Posted March 2, 2014 Report Share Posted March 2, 2014 I guess the directions didn't lie brother. <dontknow> Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2014 Report Share Posted March 2, 2014 Loose barrel will DEFINITELY cause that, brother. Check out the post from survivalshop on diagnosing his buddy's CMMG rifle with a loose barrel nut... Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 2, 2014 Report Share Posted March 2, 2014 (edited) and shoot my first group, it is way left, EDIT - $HIT! I lost a whole response in this one! :rant2: Edited March 2, 2014 by 98Z5V Quote Link to comment Share on other sites More sharing options...
Dane Armory Posted March 2, 2014 Report Share Posted March 2, 2014 Try to fix it by ALL means possible before you Loctite it. Quote Link to comment Share on other sites More sharing options...
Zebra644 Posted March 2, 2014 Author Report Share Posted March 2, 2014 (edited) Thanks Tom, I saw Shibi's 308 issue w/ his free float tube and after he torqed his down it solved his problem. I also did some google foo and depending on the type of material the barrel nut is made from i.e. aluminum can affect the torque value. I watched the first guy do it by hand and and figured since he builds so many, he could do it by feel. The second guy took it to 30 back it off than to right around 80 and he used a tourqe wrench. I am hopefull that this solves the problem. I can see how 1 the front sight being a little cock eyed can cause a rear sight to bottom out. And 2 with a barrel moving in and out I can see how the groups opened up and could casue the sights to also bottom out. I did have a few FTEs and FTFs which I have never had on this rifle when I used the original upper before changing out. That is also a sign of a loose barrel nut. The fit between the barrel extension and the reciever is a nice fit. I just wish the 1st guy would have listened to me and saved some virgin ears, ammo and time lol. Edited March 2, 2014 by Zebra644 Quote Link to comment Share on other sites More sharing options...
Rsquared Posted March 2, 2014 Report Share Posted March 2, 2014 And that would be why the rest of us build these things ourselves. Also.....there's no one else to blame when one of them doesn't run properly. The pain (read aggravation) of dealing with someone that doesn't put these things together right, can be unbelievable. Plus....it could be (will be) harder to diagnose/repair without actually having your hands in it. You only pay for tools once.....but they will help you out multiple times. Just my opinion. Quote Link to comment Share on other sites More sharing options...
Zebra644 Posted March 2, 2014 Author Report Share Posted March 2, 2014 The last time I tried to free float a barrel, I over torqued the barrel nut and over indexed causing my rear sight to bottom out and not co-witness. I learnt the hard way that I am not savy to tourqe values lol. Thats why I let a armorer do it especially on a $200 billet upper receiver lol.By the wat the trigger is of the same configuration as a NM just not as smooth. I'll get it back to you this week with all the stuff it came with. Quote Link to comment Share on other sites More sharing options...
Rsquared Posted March 3, 2014 Report Share Posted March 3, 2014 Cool. That's what I figured. Quote Link to comment Share on other sites More sharing options...
shibiwan Posted March 3, 2014 Report Share Posted March 3, 2014 If it doesn't work, just use a BFH and bang the nut until it tightens and lines up the gas port holes! :D Quote Link to comment Share on other sites More sharing options...
Zebra644 Posted March 8, 2014 Author Report Share Posted March 8, 2014 (edited) Loose barrel will DEFINITELY cause that, brother. Check out the post from survivalshop on diagnosing his buddy's CMMG rifle with a loose barrel nut... Tom, I am not worthy as you are 100% right on again. The 80 lbs of torque did the trick I had reset the zero on my windage to mechanical zero using the marks on the back of my Troy flip sight, dead on and only 3 clicks to the right on my Aimpoint PRO. The groups tightened back up to the way they should be and I put 3 mags through it tonight and she didnt skip a beat and stayed zeroed. :banana: Edited March 8, 2014 by Zebra644 Quote Link to comment Share on other sites More sharing options...
98Z5V Posted March 11, 2014 Report Share Posted March 11, 2014 Right on, brother - I'm just glad that thing is running like it should be. Now, where's my Navy buddy that thinks I'm full of $hit?... <lmao> Quote Link to comment Share on other sites More sharing options...
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