Yup, done it.

The benefits.

Faster muzzle velocity = flatter trajectory.

The down side.

Lower projectile weight = lower FPE.
Ability to power through big bones at longer ranges.

If you are reasonable with your choice of shots, there should be no issue using a patched roundball out to 50-75 yards. You might me using a ball in weight up to about what, 170 grains?

I have taken 3 elk and 4 or 5 deer with a ML, getting old so I can't remember for sure. The elk were all taken with conicals, but I did take a deer with a patched roundball once. There was no issue with the hit, lung/heart at about 30 yards.

I have yet to shoot at an animal at a range of greater than 40 yards with a ML. Using a ML is about getting close and making your one shot count. Live by these two rules and you should do just fine. Go get 'em.