Welcome aboard, MI149!! If they're like the Versa pack, the firing pin is not in a different location, the rimfire barrel's bore is off center and the frame is a centerfire frame, SB1(low strength) in the case of the Versa Pack. The combos would be on an SB2 rifle frame and the bores offset on the rimfire barrels. Unfortunately, no one has a combo yet that has reported on it, the last time anyone contacted H&R, they weren't in production yet.
Tim