"I've shot round ball and patch for 9 years now. I'm thinking I would like to get a little more accurate. can anyone help me make a good choice for a bullet to shoot out of the ole traditional Lyman Great Plains .54 cal with a 1 in 60 twist?
-are sabots werth shooting with my gun?"
The bullets will never match the accuracy of you patched round balls in a 1:60 twist. You would have to get a barrel with a faster twist for that, and even then they probably wont be as accurate as your original.
If you need more energy downrange then yes on the bullets, more accuracy, No.
I've played around with the LGP rifles quite a bit. I own two. A .50 percussion, and a .54 flinter.
They seem to like 75grn fff, with .015 to .018 patches, and .535 balls, .495 balls for the .50
I haven't found one yet that you couldn't get to shoot 1" groups off the bench at 100yds with open sights. Think what that might translate into with a decent scope.
Practice your loading technique so its always exactly the same, and keep trying different stuff.
Those lyman Great Plains Rifles are the best non-custom mzldrs out there