I have a new Optima Pro and I just bought last night a Bushnell Banner Dusk and Dawn scope for 99.00 and it's on RedHead rail and rings that cost about 55.00 all at BassPro shops.
No Optima or Kodiac to tell you about so what I'll share you is from the rifles that I have...but
One problem, not all ring makers have the same heighth medium rings. But for the most part medium ring should answer your question. All of my 40mm objectives scopes are in medium rings.
__________________
Keep on Shooting Muzzleloaders they are a Blast
I've got an Optima, and could not fit my thumb under the scope to cock the trigger with heavy gloves. So, I opted for putting high rise see-thru mounts on it.