Originally Posted By Green0:
We have not had any report of a 17-4 bolt being run to failure. Our testing was to 6000 rds on an 11.5 carbine gas about half suppressed and half with a blast shield. The ejectors in that bolt have 17-7 springs and those don’t experience temperature fatigue and cycle fatigue like the music wire, so this promotes greater longevity of ejection reliability than std equipment. The bolt has some geometries that reduce lug stress by more than 50%.

The more affordable carriers mil-spec bolts are carpenter 158, and that material has been known to run ~11,000rd service life.