The M107A1 is designed for suppressor use while previous Barrett .50BMGs rifles were not. Attempts to suppress those proved to be damaging to the rifles. The .50 suppressor for the M107A1 is the only suppressor Barrett currently makes in-house. I'm not privy to warranty info on the guns pictured as none of these models are currently available commercially yet.
The MRAD is set up as submitted for PSR competition.