Diameter vs Friction

[FredBuddy]

We're talking 45-70. In my studies here, I've learned about using cast boolits that snugly fit in fireformed cases. I got the lyman mold that drops clip on wheel weights at 457, then I powder coat them to 463, expand the case mouth slightly, and load them. They cycle fine, drop in the chamber with no effort, and shoot accurately. This in a 2007 JM Marlin cowboy. However, the barrel seems to get noticeably warmer to the touch than the same powdercoated boolit sized to 460.


The goal here is to not overwork the brass by resizing, and avoid the unsightly bulge of the expander plug. The 460 boolit is too loose in the unsized brass, so the brass must be resized, requiring more belling of the mouth and resulting in the expander plug bulge.

I haven't tried lubing the boolit to see if friction will be reduced, and I've toyed with the idea of reaming the sizing die slightly in order to get the snug fit for the 460 boolit. The dies are RCBS cowboy dies, and I have a NOE expander plug that measures 464x458.

Any thoughts?

Should I be concerned?

P.S. This dilemma is a result of frequent reading on this great website. Thanks.

[rancher1913]

your pushing an awful big chunk of lead, are you sure you are not using to big a boolit, my old trap door 45-70 slugged at 458 and I am sizing to 459. what did your bore slug at?

[blikseme300]

Overworking brass can be a concern but consider annealing your brass after a few reloading cycles as IMHO this extends brass life a lot. The hotter barrel is probably due to a too fat CB down the barrel. How is the accuracy when comparing the 2 different sizes? 2.5thousands sounds like a very thick powder coat and the possibility of displacing the center of mass will probably lead to poor group accuracy at range.

[Bzcraig]

Can't help with your question but I did wear the same patch as your profile picture.