Bushmaster ACR Semi Auto RifleThe Bushmaster ACR or Adaptive Combat Rifle features an adjustable gas piston system which runs cleaner and better than it's direct gas impingement counterparts. The ACR is a modular system which allows you to swap out barrels, stocks, and even hand guards. This particular version comes standard with a polymer hand guard and a folding seven position telescoping stock. Additional it features a 18. 5" cold hammer forged barrel along with ambidextrous