Interesting, H&R offered very few long action (L61R or AIII) Sako round top actions in their "Ultrarifle". Most of the H&R LA's were built on FN Mauser actions. The H&R round tops that I've seen were unique with two holes in the right side of the rear receiver which were filled with filler screws.
The only other manufacturer that I'm aware of to use a round top long action was Magnum Research, but they used the L691 which was a much later model.
Did your rifle come with scope bases? The round tops are a PIA to find bases for!
