Which of the 3 would you use on a mature bull bison?

.340w/ 250gr,or maybe275gr or 300gr

.375w/ 300gr

.458 w/ 500gr

Open to other loads, give reason and load if you can.

Of those three it wouldn't make any difference. I would likely jsut pick then one that I shot the best. All ore more than enough cartridge for bison.

I picked the 375H&H, because it's the only one I own of the 3 to choose from. If I knew my shots would be short the 375 would be fine. If I thought my shot would be over 200 yards, I would take my 300 RUM, plenty of gun for bison!

What about the .45-70 or .450 Marlin? I picked the .375 because I think the other two are a bit overkill for bison. But I guess if you don't mind the recoil they'll do fine...

Of those listed to choose from...proberly none of them. To me hunting such a beast is akin to the historic tales of the early West. That said, it deserves a equally classic and stylish cartridge -45-70.

I hear ya on the .45-70, a gun that I don't own.....the .458lott is kin to the .45-120, very close from what I've read, so in some sense its getting back to buffalo variety from back in the day.

I figure of them all the .458 lott is perhaps the most similar to the .45-70, though certainly amped up, ie like a .45-120, which is I guess 50grs of more powder....maybe the .375H&H is the most similar in bullet size/power....to the .45-70 though.

From what I've heard/read it sounds like bigger and slower is a better combination than faster and lighter....one reason I'm considering a rifle aside from the .340wby, or perhaps loading it up with 275 or 300gr.

Though I have never hunted Buffalo I have a friend who shot one a few years ago. Kind of like shooting a target at 100 yards for him. 140 gr from his .264 Win Mag., full broadside. One shot.

Not the medicine I would use, but I believe you already shoot a .340 wby. Big Bullets that stay together would be great medicine for the shot. Perhaps Barnes TSX at 250 gr or the 250 gr Accubond from Nosler.

The buffalo probably won't even twitch when he hits the ground.

Could be a good excuse to buy a new firearm I'm thinking....if that doesn't happen it'll be the .340 w/ 250gr.

.375 and .458 are both on the eventual list of rifles to get...and would be fun to get either and use it on a buff, break it in right.

Sharps - .45-120 be done with the whole guessing game.

45/70 buffalo bore rounds