A rifle cartridge, whose mouth will fit over a .357-359 diameter bullet, with some to spare. .375 H& H comes to mind.
Why? I'll tell you why. Lousy groups and leading with my 357 magnum. I miked the supposedly bore +.001 sized bullets from a local caster, and my Hornady swaged SWCHPs... .355-.356... the same diameter as 3 brands of jacketed/plated bullets.
But, that is 9mm size!
No wonder some ammo shoots lousy in .38 caliber! It can't be doing anything good for accuracy!
The swaged Hornadys are really soft, so will probably obturate to fill the bore. But, as for the rest, I am going to dig out my casting equipment, buy what I need, and cast my own from now on. I have LOTs of lead to add to the wheelweight I have waiting.
Now, about the Rifle cartridge...I will cut the head off, and use it as to free cast bullets from the lube melted in a cake tin, before I size them. They used to call 'em "Kake Kutters" Try as I might, I can't find one that is manufactured today.
"Look Cake Cutter" up on da'Bay, and you get...you guessed it...Wedding Cake cutters, etc.)
The diameter should slip over a .358 cast bullet, with some to spare, but not too much. sooo...it do need to be a tad large. Anybody have some old .375 H& H or similar neck size brass they will sell me a couple of ?
Or, if you are a really old bullet caster, and have a spare .38 size Kake Kutter you are not using, let me know how much you will sell it for.
I will give it a good home,
Promise!