just curious, have you ever purchased a rifle specifically for cast bullet use?
If you've gotten into seriously trying to specialize in use of cast bullet rifles , you are almost forced
to do some research, into bore size twist rates, yes your rifle land & groove designs does mater.
as does the cartridge case volume and powder burning rates you intend to use.
btw its a rather well documents fact that as the bore diam. increases the projectile mass rapidly increases ,
and potential irregularities in the cast projectiles become less critical to accuracy.
this tendency varies with the cartridge and bore size and intended velocity,
but the 30-45 calibers tend to have an edge if ranges over 200 yards,this becomes a factor.