I've shot powder coated bulleys through my 40 cal. open gun. I had absolutely no gunk or lead in the comp. after 150 rounds of 172 power factor loads. I use Harbor freight powder coat, I love it.
Lee just came out with a replacement primer feeder that eliminates the problem with the primer slider. I replaced mine on my loadmaster and it feeds primers slick as can be.
The recoil spring was replaced with a new Wolff spring about 300 rounds ago. I doubt the lockup is the problem as I've been shooting this gun since the early ninetys. I think I'll try some Win. White box just to rule out my reloads. I just don't know what else to try.
I've got a TZ75 that I get intermittent light primer strikes. I replaced the firing pin with one of Hennings long pins and removed the firing pin block. I've checked for high primers but thats not the problem. The problem is random and can happen at any time. Anyone have any ideas where to look next?