I installed an 18-lb 1911 spring back in May, 2012 and everything worked fine at that time. Forward to last week-bolt wouldn't pick up the next round-could I already need a new spring? I hadn't made any changes since that time-in fact hadn't shot it since June. Was using the same ammo--#4 birdshot. Will check the gas piston area and order a few 1911 recoil springs.