Let's see now.... Keep in mind that I have not reamed or altered my chamber, have not even polished it, I wanted it to 'wear' in. For the first 50+ rounds the empty case would not extract without the help of a dowel rod dropped down the bore, after about 100-150 rounds this problem is all but gone. This may not be acceptable to someone who is hunting with this rifle.
1. I no longer size my cases, simply de-cap in a 45-70 die, re-prime and load. I suspect that the chamber dimensions are so tight that the brass doesn't expand much, if at all. So far all of the .378 bullets fit just fine.
2. After loading I use the 38-55 sizing die with the de-capper removed to put a taper crimp on the cartridge. This isn't to crimp the bullet as much as it is to get the cartridge to chamber....tight chamber, remember. (next reloading I'm going to trim the cases a few thousandths to see if I can eliminate the taper crimping.)
With these chamber dimensions I can see where it would be relatively easy to reload this cartridge while sitting around a campfire....just de-cap, prime, add powder and bullet. Makes me wonder if that was the objective of those old, 'odd' chamber dimensions.
If I remember correctly when I slugged the bore it measured .379 to the bottom of the grooves, at any rate the bullet seemed a bit small for the bore. Apparently the bullet bumps up in size when firing.
I'd certainly recommend this rifle to anyone who enjoys casting and shooting their own bullets, it does take some fooling around to get it to shoot well, but it certainly will do that!
Roudy