To be honest, I don't like 338WM as a Buff calibre, initially
from PH's not liking them and then over the last few years I had no choice but to use one and it doesn't kill emphatically
- it will put them down but they will / can get up and almost
always need a follow up shot. The above seems to apply to Medium sized buff - shot 4 in 30 seconds tis year and ALL needed follow up kill shots but the first shots were good
and stopped them running.

I'm a 375 man myself.

318WR - I use it as I have 3 of them and I'm a traditionalist but I would put it in the same camp as the 338WM.

Nice to use but need to pick shots.

Funny enough, 2 of the charges I've faced have been with the 338WM, one Buff I hit in the neck and she turned (thank god) and the Scrub Bull I just flattened with a brain shot but any gun on either would have done the same so it was a case of use what I had in my hand or die !!!

So no, I would not recommend either as a main Buff gun on a Trophy Hunt. If it's all you own, yes, use it but my suggestion would be make sure you have someone else if your not or don't shoot Buff often.