Not sure without looking at it but you can't use one designed for a normal AR-15 buffer tube because the 15-22 integral tube has the lower extension for the stock notched lower extesion going all the way to the receiver for extra strength. A normal AR buffer tube has that stop short so the end by the receiver is just the round tube. And since you have to slide one on the end of the tube for the 15-22 you have to use one that has the lower cutout for the stock's notch extension. An AR-15 one with a round hole is put on by removing the castle nut and taking the stock off the receiver, putting it on and remounting the stock. Can't do that with a 15-22. What ever you get it has to have the round buffer tube hole and the cutout below that for the stock extension. Also can't use any of the ones that are designed to replace the locating plate below the castle nut. That is what I use on my real ARs. That QR type should be used up on the front of the handguard or way down at the end of the stock.

This is an example how mine looks:
http://t1.gstatic.com/images?q=tbn:A...YfoQD4xzEjHLVb
Ok I looked at the MCTAR-30 and it should work as long as there is a screw below the lower part to clamp it tight to the polymer tube. I am not a big fan of the full sling type attachments because any thing used at this point on the rifle will be a single point sling not a full 2 point one and I don't like the idea of so much play in a single point location.