You'll have to modify your 15/22 to work ans they have a fixed adjustable stock tube. The PRS is designed to fit over a FIXED stock on a smooth round barrel extension / buffer tube. Look at the diagram how it is a cylindrical hole.

You'll need to remove the 6 position locking dents in your 15/22 rail, and either machine off the knob on the bottom of the stock or make a cutout where the retaining plate goes on a ream M4/M16.

Basically the same issue you'd have if you tried to mount a UBR stock on one.

The ACS will work without any modifications. Look at the wire diagram and see how it is a cylindrical hole with a rectangular hole below it, that is the shape of the fixed tube on the MP 15/22.

KBK