MasterPiece Arms recently introduced the second generation of their take on the tactical sporting rifle, the MPAR 556 Sporting Rifle Gen II. This latest model upgrades the bolt hold open, the handguard, the gas block, and barrels.

The new bolt hold open keeps the bolt from closing after the last round from the magazine has been fired, and rather than using a bolt release lever or button after inserting a new magazine, the shooter simply pulls back on the charging handle and...