Sean Wilson`
WB
Friday, April 15, 2022, 17:19

I got into reloading when back in 2009 with that shortage....started converting the 41's shortly after the first 610 purchase in 2010. As for that shoulder, I rigged up a thing that sits on top of the shell holder, centers on the primer pocket, and pushes the entire case into the die up to the rim. Then I zip off that shoulder next to the rim with a file as it spins on a dowel I chuck into my drill. It works pretty good, but I just ran across a case head swage die on CH4D that would likely do a much cleaner job of it.

I'm not sure why the trim length was sticking in my head so much....I just did the math on 0.035", and it's less than a millimeter, so probably negligible with regard to starting loads. I think the combination of factors with case length and transitioning to the magnum powders started to overwhelm me. Not to mention that I've been mostly dormant with the reloading the past 5 years, and I'm not too proud to ask what others might advise.

Comparing the case dimensions of 10mm mag and 401 powermag, the cases are pretty much the same diameter from head to mouth....so I'm not so far off with re-sizing and trimming the 41's. Just seemed like I trimmed more off the length than I actually did....lol.