BU, You're asking questions a lot of newbies to cast shooting ask.
Here are a couple of basics that work for me.
I like my bullets to be at least .002 in larger than bore size. If they're powder coated, including the coating .003 in.
As for the cartridges you're going to load for, how hard do you need to cast?? Anything harder than Brinnel 22 is mostly a waste of tin, especially if the bullet is powder coated or has a gas check.
You can shoot powder coated bullets, without lube, to some very decent velocities.
Some rifles shoot lubed bullets, with a gas check better than they do powder coated.
At first I thought it was the type of rifling or width of grooves. Not so.
You need ''faster'' powders to help cast bullets obturate properly for good accuracy.
Flat nose bullets shoot just as well and often better than pointy or long ogive types.
Getting any bullet closer to the leade will almost always be conducive to better accuracy.
Your Ballard, likely has a barrel bored especially for cast bullets and will likely prefer bullet with a Brinnel rating around 15 and it may also prefer Paper Patched bullets.
If you aren't casting/sizing/lubing/powder coating your own bullets, contact the maker, such as Bullet Barn and ask them how hard they cast their bullets.
Unless it's specified, most manufacturers of cast bullets keep their tin mix to give them a Brinnel hardness level around 18, which pretty much covers all situations reasonably well.
