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Discussion Starter · #1 ·
Ok, so was putting in a new barrel on the 16, screws came out fine. No issue. Barrel slid in fine, tightened in the correct sequence, then went back to torque each to 62in lbs. First 5, no problem, clicked and set. 6th (front right for me) is set in, even to the depth of the front left, but will not torque down, it just spins. I can back it out and retighten it down to the 'correct' depth of the front left, but still just spins...

thoughts? Stripped? Solution?
 

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Discussion Starter · #3 ·
Screw looks good, exact same as one on the left. Removed the barrel again and pushed both through, no visible damage. Looked at holes on the barrel and no visible damage to the threads either. I'm perplexed. I tried putting them barrel back on and just tightening the front by a light screwdriver. Left still good, right same problem.
 

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Is the new barrel assembly causing issues? Maybe try putting the old one in to rule out that the screw are the issue. I would double check the threads on the u front trunion to make sure they are not tweaked
 

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Discussion Starter · #5 ·
By new barrel I should have said its the old assembly, just cut down. Not seeing any issues on the threads, but I'm gonna stare at me for a while to see if something appears, the pictures I'm taking don't show anything really to post.
 

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Discussion Starter · #6 ·
No difference in the screws no matter how hard I look. After about 5 minutes of staring at the threads on the assembly it looks like the one side is shallower, doesn't look stripped, just probably shallow enough to cause this problem. As I hadn't tried moving these screws until now, is it possible it came from the factory with a shallow set of threads? Would FN basically be my only option?
 

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Discussion Starter · #8 ·
Took it apart, tried to tighten it again (not torque, just using a t25 screwdriver to hand tighten. Now both front screws are doing it... :cool:
 

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It sounds like you're just not catching the threads. I swapped barrels a couple of times recently (to the engravers and back) and those front screws required me to push in firmly with the driver to even catch the threads so I could tighten/torque.
 

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This!

and those front screws required me to push in firmly with the driver to even catch the threads so i could tighten/torque.
 

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The screws appear fine, as Akitainu stated, push hard to get them started and see what happens...
 

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Discussion Starter · #14 ·
Ok I pushed down with as much force as I can muster, nothing catching on either side. probably going to have to replace the lower barrel support. Might as well replace the screws just in case, eh?
 

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Discussion Starter · #15 ·
Yeah, that last try to really catch the threads definitely looks like I stripped the lower barrel support threads, there's metal shavings in the receiver. So, I'm assuming heating the torx screw that holds in the lower barrel support is the best way? What's the best way to remove the forward Torx screws?
 

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Discussion Starter · #17 ·
Here is what my spare rail looks like.
View attachment 36307

Heat the Torx with a heat gun before removal.
Thaks storm, I'm going to try it with the current torx screws, but if it turns out theyre a bit thin compared to the new ones, what's the best way to remove them from the receiver?
 

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I wasn't under the impression the barrel support screws needed to be heated at all. I know all other fasteners on the upper require heating to at least 300 degrees to release the Loctite grip but the barrel screws are "captured" meaning there should be no requirement for heating. As for removing them, keep in mind there is a spring which captures the screw and makes the clicking sound, DO NOT lose it once disassembled. Good luck and keep us updated. :?
 
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I wasn't under the impression the barrel support screws needed to be heated at all. I know all other fasteners on the upper require heating to at least 300 degrees to release the Loctite grip but the barrel screws are "captured" meaning there should be no requirement for heating. As for removing them, keep in mind there is a spring which captures the screw and makes the clicking sound, DO NOT lose it once disassembled. Good luck and keep us updated. :?
I was referring to heating the single Torx bolt that attachés the rail to the barrel support.
 
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