Make sure your Marlin doesn't have a micro groove barrel. If it does, it'll never shoot lead well. The micro groove barrels fill up with lead, and your 25 yard groups will look like 40 yard shotgun patterns.

On another note, the manufacturer doesn't recommend H-110 for plain based lead bullets,(as opposed to gas checked or jacketed) as the powder burns so hot, it melts the back of the bullet and leads the hell out of your barrel. (I can confirm this; 1 cylinder full had my barrel coated with lead!)

Well, that's enough out of me! I hope I didn't discourage you.