TAC21 Gen 2 Chassis System uses AICS-type magazines and AR-type pistol grips, receiver extensions/buffer tubes and buttstocks(sold separately). The easiest and usually best way to complete this chassis is to purchase MDT’s AR Pistol Grip and Skeleton RIfle Stock, and of course at least one magazine for your action and caliber. You will get benchrest accuracy, superior ergonomics, versatility and modularity. Straight-line desing means that the recoil comes straight back and does not raise the barrel, which translates to less felt recoil, quicker follow-up shots and better accuracy. Because of this design, the chassis comes in 4 pieces, with all required mounting hardware. Installing can be done in less than an hour, and no bedding is needed.