I haven't noticed any difference between the 2 trigger springs. Might be because the trigger is just a simple on/off catch for the big sear that is holding all that hammer spring weight. No "stages" to it or adjustments can really be made on it. One end of the spring is in a round inset in the top of the trigger and the other end of the spring is in a matching inset on the sear itself. I had hopes when I put in the lighter spring, about half the strength of the original, but there was no dramatic difference I could see. Did you see Dan's posts about his LEE mold at first casting to .354 and then he raised the lead temp and then it was casting at .356? I hadn't really noticed since my casts pretty much go straight into the swage press - even got a new round nose punch coming for the press as well - but I do know they stop in the .357 sizing die and need to be tapped through so I guess my simple Coleman burner setup might be running hotter than your rig as well. I have been casting "lead" from 2 different guys on eBay so I don't really know if it's "pure" or not. I found a deal at a local tire shop and they will sell me a 100 pound bucket of wheel weights for $40 in a couple of weeks, but I have never messed with those before.