Yes - the .43 is an interesting round. A number of them are used in winter postal antique military bench-rest matches through the cast bullet association - the M1871/86 with .446 groove diameters.

I haven't used mine (a carbine) for hunting, but there is nothing here in British Columbia it wouldln't kill - easily. At 7 pounds it has nice carry weight, but not so nice recoil absorbsion.
The common twist rate for them was 20", so they will stabilize up to 500gr., although the Double Rifle might be regulated for a 340 to 370gr. bullet.