Originally Posted by
PX4 Storm Tracker
@141,100 rounds on my PX4 .45G range pistol I had gotten a light strike that day in double action with an S&B 230 grain FMJ load at the range. This D spring had 92,730 rounds on it before giving a light strike. I retired it.
I installed a D spring that had 9,248 rounds of use in my wife's SubCompact 9 range pistol. I put 200 rounds on it so far with no light strikes.
I have an observation from experience that seems to hold true here. When my double action pull gets under 6 lbs light strikes can occur. My old D spring was delivering a 5 lbs, 14 oz DA pull (I knew it was just a matter of time). This newer spring delivers a 6 lbs, 3 oz DA and a 3 lbs, 8 oz SA.
I have continually monitored locktime to make sure that the old (original) hammer and trigger bar are still bringing the hammer as far back in the DA cocking. Locktime remains unchanged after 141,300 rounds. The firing pin channel was just cleaned and the fire control unit cleaned and lubricated... so there are no mitigating factors, just hammer spring strength as far as I can determine.
92,730 rounds of use from a hammer spring being slammed back to compression by .45 ACP is still very good for a $10 spring.