Buttstock question

[Slater]

I've got a Bushmaster A2 target model with the standard A2 buttstock. The stock has a slight amount of rotational movement. Nothing serious but just annoying. Any way to tighten it up?

[ScottsBad]

Try tightening the screw at the end of the buttstock. It screws into the back of the buffer tube. Maybe put some blue loctite on the screw.

[Dionysusigma]

Or if you need to go further:

1) Remove the stock (watch out for the rear takedown detent spring!) by removing the upper screw on the buttplate
2) Remove the buffer and spring
3) Remove the receiver extension slowly, while making sure the buffer retainer and spring don't go flying out
4) Clean and de-grease the threads on the receiver extension and where it threads into the receiver, and apply blue Loctite
5) Reinstall extension, buffer retainer and spring, and buffer and spring
6) Clean and de-grease both the screw hole in the receiver extension and upper buttstock threads, and apply blue loctite
7) Reinstall takedown detent and spring, slide the stock on, and reinstall buttplate screws

[Krazykarl]

Be advised that my BM A2 had red loctite on those screws. Took some careful effort to not bugger up the screw heads.

[JasonB1]

Be advised that my BM A2 had red loctite on those screws. Took some careful effort to not bugger up the screw heads.

If that is the case it would likely unscrew the receiver extension instead of the screw.

[26 Inf]

If that is the case it would likely unscrew the receiver extension instead of the screw.

This made me think.

My theory: if you held pressure, pushing the stock toward the end of the receiver, the end of the rifle extension would only unscrew until it butted against the butt plate, then jam. This should allow the upper buttstock screw to turn.

Am I wrong? I've only messed with A2 Rifle Stocks in armorer's courses.

[JasonB1]

This made me think.

My theory: if you held pressure, pushing the stock toward the end of the receiver, the end of the rifle extension would only unscrew until it butted against the butt plate, then jam. This should allow the upper buttstock screw to turn.

Am I wrong? I've only messed with A2 Rifle Stocks in armorer's courses.

Might work. Would come down to which had more oomph, the pressure forward to keep the nub locked in the back of the receiver or the inclined plane action of the threads. Also the issue of whether the A2 spacer would bind or be self lubricating between the extension and the plate.

If it doesn't start moving quick, try sticking the tip of a soldering iron in the vent hole to cause any thread locker to give it up.

[556Cliff]

Stock screws use Nylok not Loctite.

Loctite would basically bond the two parts together but Nylok is just an interference fit, same thing as Magpul pistol grip screws.

Also, as long as the receiver extension was torqued to spec it should not unscrew from the receiver just from loosening the stock screw.

However, my past disassembly experience with a Bushmaster factory assembled lower receiver with a rifle RE proved that it was just barely past hand tight. Though I still had no problem removing the stock screw.

[81mmcat]

The colt A2 buttstocks I've had apart had a thin o-ring on the stock tang that indexes into the receiver with out it there is more play. http://www.specializedarmament.com/—-buttstock-fixed-·-rifle/o-ring-fixed-buttstock/

[JasonB1]

Stock screws use Nylok not Loctite.


Learned something new today. Had always assumed it was the swipe stick version of Loctite.

[lysander]

Learned something new today. Had always assumed it was the swipe stick version of Loctite.
You were both sort of right the first time. At least for Colt screws, made per the drawing.

It's a Nylock brand medium strength thread locker, pre-applied to the threads, not the usual nylon button inserted in the threads-type nylock fastener.

Other brands may use other type pre-applied threadlockers.

[LMT/556]

Movement in my LMT A2 lower was eliminated by tightening with an impact driver slot head in a 3/8 in ratchet while applying enough force to keep the driver in the slot. It takes more torque than practical through even a large screw drive.