The Optima/Pro is a muzzleloader only frame, the Optima Elite frame is much stronger, intended for use with centerfire rifle barrels in addition to muzzlelaoder/shotgun barrels, is offered in 300 Win Mag(when they get em to market!!) and several other calibers, 222, .223, 243, 270, 7mm-08, 308, 30-06 and 45-70. OE barrels won't fit on an Optima frame and vice versa. The design is similar tho, but not in material and strength.
Tim