I can't swear by the spring, I just have the one it came with. Contrary to popular advice, I tried CCI standard velocity lead heads. 700 + rounds with no failures. 2nd best has been CCI mini mags - roughly 2% FTEs. Serious failures have been Federal anything - 5% or more FTE or FTF. My biggest problem has been that when I take the compensator off to strip and clean the pistol, I have to redo sighting it in from scratch afterward. The front sight seems to jiggle around a bit once the compensator is back on - never had to do anything like this with my Model 41.