I own both.
But your life will be easier with the 50 cal.
Just more loads and stuff for the 50.
Walk into any remote store that sells muzzy stuff and they will have 50 cal stuff.
54 cal not so much.
Both kill elk just fine.
Totally agree.
Still hunt with my 54 sometimes.
Back when I was younger (and sabots weren't legal, I think the 54 had a big advantage.
Now, I shoot the same hard cast lead round out of 50 and 54.... just different sabot.
50's have all the love, so all the options.
54s are becoming relics..... IMHO.