15% extra power - Griffin Armament Extra Power Buffer Spring

Used the A2 version in BCM Mk2 system with a T2 buffer for a SOLGW 13.7 midlength gas upper. Maybe don't need it but figured why not? Very smooth and soft recoil impulse. Cycled but NO lock back with Wolf steelcase. Worked without malfunction with PMC bronze .223 and all my m193 spec ammo from Winchester, IMI, PPU, GGG and even Wolf Gold.