My rifle is a 1:48

When shooting a round ball, the best accuracy is at 75 grains in that gun. However, they will leave an exit hole only about 50% of the time on a deer. You'll find that ball flattened out to about an inch lodged on that opposite skin.

Now the reason I use that Harvester 270gr bullet is because it's the only bullet I have tested in the last 15 years that will shoot dead on (windage) at 100 yards without adjusting the sights (since the Harvester, roundball, and Hornady Great Plains will all shoot in the same hole at 50 yards). Heck, of everything I've tested the Harvester and Hornady XTP are the only things that even hit paper at 100 yards without moving the sights - and the XTP are 6" left.

I'm not all that pleased with the bullet I've been using despite dropping every deer in it's tracks. I'm going to buy a pack of the 300 or 350gr and see if they happen to be on at 100 yards. If they aren't, I'll go back to the 270.
I'm not moving the sights because if something stupid happens with my bullets, I can fall back to some other choices.