You can buy a conversion kit for the AR 15 that utilizes a piston system. The fact is, the SCAR does not really offer anything new for the price.
The Bushmaster ACR(Formerly the Magpul Masada ACR) at least attempts to put more versatility into it's new multi-caliber tool less
assembly/disassembly system, as well as it's ambidextrous controls. The jury is still out on the reliability of this weapon system as I don't believe
enough private sector hands have been able to test it yet, and there simply hasn't been ANY battlefield testing done as far as I know.
I simply wouldn't buy either the SCAR or the ACR until 1. the price came down, and 2. the reliability of either system is proven. It may be a while
before I abandon the AR/M4 platform for something else.
edit on 9-6-2011 by projectvxn because: (no reason given)