Doubletapp23,
I came into a .22-243 quite by accident. It was abandoned in one of my selfstorage units. It came in a canvas zippered gun case with a pocket that had a box of reloads in it. I thought I had a .243 until I looked closer.
The reloads were .22-243 Winchester which has the same shoulder angle as the .243 Winchester........so I thought that's what I had.
The rifle was obviously someones unfinished project made from an FN Mauser. I took someone's advice to do a chamber cast, and found that the barrel was not the vanilla 22-243 Winchester matching the reloads, but .22-243 Middlestead, which has a steeper shoulder.
I tell you this because Uncle Nick has given you good advice to do a chamber cast to make sure of what you got.....as well as give you data on case length. You might have a Middlestead version too, as they are more common and popular......and you can't tell without a chamber cast......or you could shoot reloads made with your die set and take the chance of it fire forming well.
Which dies came with it Winchester or Middlestead? I ordered Winchester dies and luckily Grafs exchanged them for Middlestead.
There are a few sources of information on loads on the internet. Few is the governing word there. Good luck with your project.
http://www.ballisticstudies.com/Knowledgebase/.22-243.html
I found some info on Okshooters.com thread 168954.
Greybeards forum:
http://www.gos2gbo.com/forums/index.php/board,91.0.html
http://www.accuratereloading.com/22-243.html
BTW, the barrel on my project was chambered specifically so that reaming inside the .243 case necks is not necessary......that depends on the smith who chambered it. The chamber cast should help you determine that also.
I ordered low-melt Alloy 4250-2 from Bolton Metal Products. to cast my chamber.
