I used to use 240grn and 250grn bullets in my 44's and 45's. I use farly hard cast RNFP's with a large flat point. A few years ago, I switched to 200grn b bullets of the same stile in both, and the deer I've shot can't tell the difference. Both the 200's and the heaver bullets go clean through both frt shoulders out to about 75yds, and that's all that's important for deer. Heaver bullets and more velosity are great, but most of the energy is expended on the other side of the deer, which is a waist for you.
The best load for deer is one that you can control, keep all your shots in a decent group, hit exactly where you want to, and the bullet goes clean through the deer, then falls on the ground on the other side. That way, nearly all the energy is transferred to the deer, providing a good wound channel and you ain't worried about the bullet traveling hundreds of yards past the deer, maybe hitting something you don't want hit.
The advantage of a longer, heaver bullet is they sometimes are more accurate at longer distances, and hold their velocity better at distance. Out to about 75yds, I can't see much difference at all.
And the 200's kick less than the 240's at the same velocity.
So I would say the 200's are fine for deer hunting.
Greeenriver