We were shown the protoype of MPAR designed and manufactured by Master Piece Arms. As a Canadian version (MPA-RC) is being planned for the near future, we decided to take a better look at the system
The rifle is operated by a short stroke gas system in the same vein as the AR180, with a triangular bolt head instead of the rather common stoner multi-lug arrangement. The receivers, both lower and upper, are made of sheet steel finished in parkerization. The prototype is very cleanly done as we do not see any welding spots on the outside. The charging handle is on left side of the receiver, rather than the right side as on the AR180.
The aluminum handguard is fastened to the upper receiver by a hex screw, and rails could be attached to the side as needed by the user. The prototype in the show uses AR15 fire control parts, but the Canadian version will be using proprietary fire control parts to relinquish any possible linkage to AR15. Overall the prototype is pretty solid, to be point of being a bit on the hefty side, as the pistol grip and stock are the only plastic parts in the entire rifle.