I have been experimenting with .45Cowboy Special brass [same length as .45acp] in my Marlin 1894 Trapper after having issues with .45 schofield brass. The Schofield’s larger rim would occasionally jam up the bolt to where it wouldn’t quite close without a struggle. Tight bolt? So I got a handful of .45CS to play with. After working out an oal that feeds 100% [1.295-1.300] [and I can get 10 into my very short trapper magazine]. It shoots swell with a 255 swc boolit but I want to move my reloading to a Dillon 550 that is permanently set up for .45acp or .45autorim. I tried to get a .45colt shellplate and the seller screwed up the order and sent me a .acp plate not a .45colt plate even though he invoiced the correct part??? Having to deal with a fleabay return now and all that rigmarole. Anyway just out of curiosity I just tried some .45colt brass using the .45 autorim ‘H’ shell plate and #4pins and I think that it will work just fine for the .45cs brass. The dimensions of the cases are pretty close other than the rim thickness. I only have 25 pcs and they’re loaded so after I’ve fired them I’ll try to reload them on the Dillon and know for sure. Don’t know if this is common knowledge or not. If this works I won’t buy another plate. Save a few $. I’ve got 250 CS brass backordered at Starline.
Okay, I just tried one on the Dillon and the primers will start to seat but the extra thickness of the AR brass rim means a deeper cut for the rim into the shellplate so the case lifts. Doh! I will have to seat them the rest of the way by hand with my auto prime and then load them. But, I might be able to recut the primer seating punch so that it sits a little higher as I’ve got a few spare punches. I recut the bottom of the priming seating punch and reshaped the set screw point and got some more height out of it. Maybe this will work.