The Masterpiece Arms R556 is a semi automatic sporting rifle chambered in 5.56mm NATO and features a 16.25" barrel, combat muzzle brake and full length rail. It features a locked bolt short stroke piston system, MPA aluminum handguard, non-reciprocating side charger with forward assist. The MPAR 556 also has a side folding collapsible buttstock and wil accept any standard pattern AR-15 magazines

Specifications and Features:
MasterPiece Arms MPAR 556 AR-15 Semi Auto Rifle R556
5.56mm NATO (accepts .223 Remington)
16.26" Barrel
1:9" Twist rate
Muzzle brake
Short stroke piston design
Non-reciprocating side charger with forward assist
MPA side folding collapsible buttstock
MPA aluminum handguard
Full length top rail
Overall weight 7.8 lbs
No sights
Black phosphate, hardcoat black
Anodized finish
Black