<p>F17-VS4â„¢ COMPLETE UPPER ASSEMBLY SPECIFICATIONS: Chambered in 17 Winchester Super Magnum Rimfire 4140 Chrome Moly Salt Bath Nitride Chamber, Bore, & Finis” Bull Barrel 11 Degree Target Crown with Recessed Muzzle Crown 1/9-Inch Twist Forged A4 Upper Receiver 7075-T6 Aluminum Hard Coat Type III Anodized Black Full Picatinny Rail Forward Assist Franklin Armoryâ„¢ Free Float Handguard (Fluted & Vented, M-Lok compatible, and an Integral Bipod & Tripod Adapter) Custom Designed 17 WSM Bolt Carrier Group Gas Piston System Design Also includes: one .17 WSM magazine that fits with all standard MILSPEC lower receivers and custom buffer. The F17-VS4 upper assembly requires an A2 style”rifle length” buffer tube and spring for proper operation. Some aftermarket trigger systems may not provide reliable ignition. Check with the trigger manufacturer to confirm that a full power hammer spring and full weight hammer are utilized to ensure reliability.</p>
