Lagopus - please check your Personal Message account on this site.
I sent you a note on your friend's rook/rabbit rifle.
Mike - the nutshell on setting up for the pinfire rifles is that they're all special and unique, but relatively simple.
The first thing I do with a pinfire gun or rifle is cast the chambers and slug the bores from the breech and from the muzzles.
I do that for both barrels, and I also run slugs through from both ends to check for bulges (which could have been hidden by subsequent barrel striking and browning or blacking) or tight spots.
It's important to know for double-damn sure what you're getting into.
I've also had numerous sets of barrels x-rayed to further my 'look-see' into what would otherwise be total unknown territory.
The circlefly comments on loading brass and proper wad column treatment is a good read - and as many things are in respect to loading black powder cartridges (shot or rifle) nothing seems to be written too clearly in stone. Great reference material though, and good to think about when you're wondering what's going on with your loads on the pattern board.
Via a chamber casting and a bore-slugging you'll quickly find out what the case-mouth wall-thickness needs to be.
My guess is that somewhere in the 99% range you'll find that your pinfire gun or rifle was built for paper tube cases.
Modern plastic hulls have similar wall thickness to vintage paper cases, so that little diddy from circlefly will likely be valuable information for anyone looking to modify modern brass cases for their pinfire guns and rifles.
Something else of note is this - you'll need to do something about securing your percussion caps and backing them for the firing pin strike --*AND*-- base wads aren't necessarily permanent. If you're looking to set up with a base wad or if you're modifying modern plastic or paper hulls for pinfire use, pay special attention to your base wads. Account for them every time you re-load those barrels. When you go messing around with cartridge modification, it's important to be especially careful of this kind of thing - and everything else while you're at it.
There's always the potential of popping a barrel by way of a bore obstruction or overload.
That brings me to powders - use real black powder.
Skip the substitutes, skip nitro-for-black recipes.
Use black powder. Goex is great, and as good as it gets for your shotshell reloading.
From there it's pretty simple.
Conservative charges of relatively equal volume powder and shot, with normal over-powder cards and lubed felt wads.
With some of the shotguns you might get lucky with simply thinning the rims of CBC brass, plugging the primer pockets, and drilling firing pin holes for use with hard bronze wire firing pins - then setting the percussion caps against the 'far side' of the case, using the barrel chamber as your backing 'anvil' for the relatively soft internal bronze firing pin.
With others, you might end up needing to go so far as making your own cartridge cases and swaging dies.
Above you'll see a steel swaging die and a series of swaged brass that I built up for my Purdey 20bore rifle.
That one was just about the most labor-intensive cartridge case development I've dealt with. The results were very rewarding though!
Cheers
Tinker
