Every body has pointed you in the right direction with regards to calibre and projectile.
Like Marrakai I own and use a 375CT however I only use 300gn round nose solids and soft nose..

You cant go past woodleigh bullets and the bonus is that they are made in Australia.

Dont ever travel to the Territory with out a spare rifle and maybe a spare scope.
I use a 1.5 x 4 x20 Leupold on my 375 CT .
I took my Ruger 308 synthetic and a 303 Lee Speed as spare rifles on my last trip to the NT.
I tried and found that woodleighs 220gn rn sn 308 projectiles worked brilliantly on pigs and also donkey so iff you are chasing a load for either of the above give me a call.
I use Woodleigh 215 gn projectiles in my 303 and must admit that they are very compareable with the 308 both in accuracy and knockdown power at reasonable ranges.

Al