I have a little used M&P 15-22 AR trainer/ plinker. 22lr. This model is probably 6-8 years old. It comes with the quad rail, and mod 0 buis. I upgraded the charging handle with a latch, magpul rail covers,hogue grip, 2 official 25 round M&P mags with plastic pulls, 1-10 round m&p mag with...