I posted this in the troubleshooting forum, but response time is slow there, and I am really antsy to get this fixed so I can hit the range with my brand new AR today, while there is still daylight.

I just installed a Bushmaster .22lr upper on my AR. However, the buffer tube for the rimfire upper will not fit inside the stock for some reason, so I left it out. I closed up the weapon, but now the bolt is pulled to the rear, with no buffer spring inside. It won't move forward, no matter what I do. It isn't stuck on the buffer detent pin, and I can't figure it out.

Any help would be appreciated. I figure it might help to pull off the stock, but I don't know how. Thanks.

remove the sock and buffer tube. push detent out of way and push bolt back in to upper.

Quoted: Push BOTH lower receiver pins open and try to wiggle the upper loose.

Negative.  The back piece on the upper that the pins slide through is blocked by the hammer.  

remove the sock and buffer tube. push detent out of way and push bolt back in to upper.

I don't know how to remove the stock.  Do I need any special tools?

Nope.  Just unscrew those two screws and unsrcew the buffer tube.

Get a BIG screwdriver, and remove the upper screw on the butt of the stock.

Remove the stock slowly, there is a spring and detent under there that is part of the rear takedown pin. unscrew the buffer tube. Don't loose the buffer detent and spring.



Collapsing stock? Need a wrench made for it. Might need a different buffer tube to use with the .22 conversion.

Quoted: Quoted: Push BOTH lower receiver pins open and try to wiggle the upper loose. Negative.  The back piece on the upper that the pins slide through is blocked by the hammer.   remove the sock and buffer tube. push detent out of way and push bolt back in to upper. I don't know how to remove the stock.  Do I need any special tools?

The stock will be held on to the buffer tube with either a flat head screw or an allen screw.
Use either a screwdriver or a hex wrench to remove it. Take care not to lose the little spring that holds the safety detent in place.
Then you'll need a wrench (adjustable will probably be easiest). There is a flat on the rear of the buffer tube. Use this to undo the tube.
It'll probably be easiest if you hold the lower with the pistol grip between your knees to undo it, unless you have a vise.

Hope this helps

Mark

Guys, this is a six position collapsible stock.  Sorry, I should have mentioned that earlier.

It looks like a big locking nut connecting the stock to the lower, do I just use pliers to unscrew that?  I tried already, but the pliers just slip right off.  Plus, I hate to scratch or otherwise damage the weapon the same day I bought it.

put a screwdriver in one of the castellations on the nut and hit it with a hammer.
That'll get it off

Thanks for the advice guys, I finally got it done.  My first AR surgery.  I feel proud!

On the downside, if my .22lr upper won't run on a collapsible stock (as I suspect) I may have to sell it, or possibly try to return it to the store I bought it from.  I await word from Bushmaster.