In my last thread, people said I should use grease and torque the buffer tube (receiver extension?) into the lower receiver at 35 ft lbs.  I don't have anything to measure the amount of torque, so I was considering using blue thread locker instead and just snugging the tube in well with a wrench.  Will this work without damaging my gun?

Just screw the tube in and "snug" it. Never had a problem.

I use blue threadlocker on my CAR stock and it works great. I lock the tube into the lower, than I tighten the tube nut with my CAR stock tool and using blue locktite on it as well. Gives me a little more confidence knowing it is locked down.

Sounds good, I'll try some low strength Loc-Tite if this grease and wrench isn't enough to hold it in place.  They said to use moly disulfide, but all I had was tetra gun grease, I hope that will work.  I figured the grease was just to avoid damaging the threads.

I have actually had a buffer tube "back out" on me, and it was a PITA to fix.

It was my first AR build.  I bought an assembled lower from an individual who should have known better, put my upper on it, and went to the range for its maiden voyage.

After about 20 rounds (cleaning the bore after each shot), the bolt carrier stuck halfway between "open" and "closed".  I couldn't budge it, nor could I open the gun.

When I finally separated the lower from the upper with a feat of brute strength, the buffer retaining spring and pin launched into space, never to be seen again.....  The buffer tube had backed out enough to let them out of their hole, and the spring is what had wedged the bolt carrier.

Range time was over for that day :^(


Later, I tried to remove the buttstock so I could install a new pin and spring, and tighten the buffer tube.  Now things went from bad to worse....  When I was turning the screw that holds the buttstock on, it wasn't the screw that turned.  I wound up taking the buffer tube out of the receiver.  

I now had a buttstock that was tightly attached to the buttstock, and no way to keep the buffer tube from turning.  I eventually had to hold the tube with some vise grips (mangling the threads) while I turned the stock screw with a screwdriver.


Cost of this little exercise?:
- new buffer retaining pin
- new buffer retaining spring
- new buffer tube
- rifle unshootable for over a week while I waited for this stuff

I bought myself a barrel wrench to torque on the new tube, and used a friend's vise, torque wrench, and anti-sieze grease to put everything back the way it was.

Lessons learned:
RTF - TM!
"snug it" ain't good enough on the buffer tube


I later bought a torque wrench and a vise at one of those Homier tool shows.  I was surprised how cheap they were.


Sorry for ranting.  This is just one of my pet peeves now.  I guess you can understand why.

Yep, I would have to say purple would probably work better than blue. DON'T ever use red. Red needs over 3000psi to break loose!

OK, the tube came loose today, so I wiped all the grease off, degreased the threads, and put some of the thread locker on there.  I couldn't find low strength, so I used the medium, somewhat sparingly.  I figured it would be too strong, so don't use too much.  I hope this works without breaking anything.  :)