Andy at Lever Gun Leather works has made me a couple of butt cuffs for my Marlin 45-70 and my Mod 94 .356 Win. They attach to the butt of the rifle and each holds 5 rounds and I opted for beat carving on the other side.
They are beautiful to my eyes and the ammo is always with the gun. He can fit any cartridge. I would take the tie to see all he offers.
Tripple k and some others offer belt slides and a .358 loop might work. With out going custom finding a cartridge slide made specifically for the .348 may be difficult.
