Lotsa luck!
Lee has sizers in .308, .309. .311 and .314, cast bullets usually do best at .001-.002 over groove size.
Commie milsurps are all over the place. I have a M44 with a .314 groove, a friend has one with .316, another has one with .310..
Might check your handi too, my .308 Win. barrel measures .3093.
I called H&R about their barrel dimensions, they have a tolerance of +- .002".
The Lee sizers can easily be opened up with a piece of wood dowel, split the end, insert some wet or dry, 240 would do, chuck it in a drill motor and spin until the size is what you need.
Don