Does anyone make an adapter or an A2 style butstock for the M&P 15-22, or do I have to mill the bottom of the fake buffer tube and make a spacer? Thanks.

I think you're gonna have to custom fit it if you really want it.  I've never seen or heard of one being made.

If a company came up with an A2 stock conversion for a S&W 15-22 they would rake in a ton of cash. I wish I had the means to produce such a product!

It would be a cool product.

What about the Magpul fixed carbine stock? Will one of those fit?

Yes.  The receiver extension on the M&P15-22 is Mil-Spec dia., the limiting
factor is that it is molded enbloc (one piece) with the lower so it isn't removable.

One caution here, the M&P15-22 doesn't have a castle nut and the MFCS is designed
with that in mind.  So a word to the wise; try before you buy.

But the fixed carbine stock is not an A2.

Ted

I tested something out for you...
If it is just a fixed stock that you want, you could use the VLTOR Arms stock.
If you want an actual A2 stock, that I can't help you with.

I've attached some photos.  The stock is for rifle extensions but can be used on mil-spec collapsible extensions as well.

It has a clip that goes into one of the "holes" for the stops to keep the stock from moving when used on a collapsible extension.
You could probably use it in the fully "collapsed" length if you shaved some material of the stock.  It's about a 1/4" away from being plugged into the first hole.
You could also extend it and use the rear clip position to fix it in place.

It's a sturdy stock, surprisingly light.  Comes with cheek rest versus storage tubes.  You could probably even add weight to the M&P tube and the storage tubes to get the 15-22 heavier if you want.
Added some photos for you to look at.  The top picture is on an actual AR with A2 rifle tube.  Middle photo is with the stock pulled out so you can put the clip in the rearmost hole.  The bottom photo is on the 15-22 pushed as far forward as possible.  In this position it cannot clip in, but if you shaved down the front of the stock it would fit.

Might want to sell mine actually.  IM me if interested.

A few years ago a guy made an adapter that let you use an AR receiver extension. I didn't see it in time to actually get one before he seemed to drop off the face of the earth. His adapter didn't have an allowance for an endplate or the protrusion from the stock that would stop rotation. His Youtube video is here:
https://www.youtube.com/watch?v=srXc5eNY9qA

I used an airsoft knock-off of a Law Tactical folding adapter on mine. An adapter would add some length no matter what since the area that you'd normally screw the tube into would be too thin to last on a 15-22. But you should be able to install an A2 with it.





I did remove some material from the rear of the receiver to it wouldn't rotate as well.