I was visiting a friend this morning and he showed me 'his' 'new' cartridge. Based on a 7.62x54 R case, necked UP to take a 41 cal. bullet. He has a reamer but still needs dies to load some more up.
Cartridge OAL is about 2.9" with just a slight shoulder. I've attached some pictures.











He currently has a Contender made up for it.

So, anything like this out there? Already done?

A friend of mine has necked his for the 416 bullet and calls it the 416 Russian

A friend of mine, named Walt, necked the case up to .45 and calls it the .450 Wally Wart.

Similar, but not the same.

Jesse Occumpaugh at JES Reboring does a cartridge that they call the 405 JES. I think that it is based on the 375 Winchester necked up to .405", with an OAL around 2.56". Since it is intended for use in the Marlin 336, the OAL is limited so that it will cycle through the action.

When I was in 7th and 8th grade, I designed a large line of cartridges based on the 7.62x54R. Didn't have the money to build any at the time, and eventually lost interest (found girls, cars, etc.), then later when I got back into wildcatting I learned more about cartridge design and decided the x54 wasn't the best case for my intended purposes.

I don't believe the 41 was part of my plans; it's neat to see the case used for wildcatting! Good thing there's a rim for headspacing, as the shoulder is looking a little suspect for the job!