I finally got my .19 Calhoon together, and now I'm trying to fire form cases. Unfortunately, I'm getting no success at all.
I've tried 13 grains of Lil'Gun behind a 32 grain bullet, but the shoulders split.
I sized the cases without annealing them, and am thinking maybe this is the problem.
I welcome advice, as I've only reloaded "factory" ammo up until now.
Regards, George.

Calhoon has a website. Perhaps they have advice there on how to fireform thier cartridges.

When shoulders split on me when fireforming I put oil on each case. Motor oil should be fine.

I don't know your cartridge at all but generally I prefer fireforming wildcats, and even conventional brass, without a bullet. I use a charge of fast pistol powder at about 25% of the weight of a "normal" charge for the cartridge, then stuff the rest with Cream O' Wheat and top it off with a wad of toilet paper, unused of course. After that is when I anneal.

I did have troubles once using Bell brass to form a Jamison cartridge and experienced the same thing you have. I found that annealing just before forming helped a bit but it turned out the brass was pretty shabby to start. When I switched to some European brass the probem went away. Try annealling before you fireform the brass, in whatever way you choose to fireform. You should give consideration to using COW. It works quite well.