I'm trying to feed a Martini sporter by Isaac Hollis and Sons; classy looking arm with a great bore that slugs .458", 5 leaf express sight, pistol grip, horn forend tip, engraving etc. It's considerably lighter than the full military versions at about 7 1/2 lbs. with a 26" barrel and full length rib. Only cases available to me were the 24g. brass shot shells and they formed nicely using only the older Lee die set that came with the rifle. The fly in the ointment is that the throat is considerably larger than necessary, presumably for paper patching. Fired brass comes out with the neck I.D. about 5 thou. larger than is required to hold a proper sized bullet, which seems to be in keeping with the neck expander in the die set. There is barely enough room for paper patching unless I cast or size the pills down considerably, but an experiment with 5 wraps of T tape ( crude I know, but effective) gave very good results.
I'm loading .458" 405s over 16 grains of Unique, large pistol primers ( rifle primers are too deep to seat flush in the shot shells) and getting perfect ignition every time. They are clocking just over 1,000 fps. with no sign of excess pressure and it produce 5 rounds touching each other at 50 yards. That's the only range available to me at the moment. So at least I have a pleasant, reliable plinking load that is fun to shoot, relatively quiet, and more accurate than I expected from a 130-odd year old relic.
I'm still at a loss for a more manly load. No matter what I try with 4198, as recommended in Ctgs of the World and other places, I can't get the stuff to ignite with or without filler. The primer puts the bullet into the bore about 3" ahead of the chamber but virtually none of the powder is burning. Same can of 4198 works fine in a .222 so it's not wonky powder.
I will try some of the other powders recommended above, but the vast unused space inside that great beer can of a cartridge concerns me for warmer loads.
KH
