Leftoverdj-
I also have a H&R Ultra Rifle in .450 Marlin and I'm planning on casting for it in the future. If you don't mind a question, I was curious if you have any info on the .450 Marlin using heavier (450 grns +) bullet weights for cast. I was thinking that possibly the heavier bullet weights take up too much case capacity; but I haven't seen any info presented on the BB's or in print to that effect. I'm considering ordering a mould for a 475 to 500 grain LFN style cast bullet. I'd hate to order a mould that was too heavy for this caliber.
Just hoping you could shed some light on the .450 Ultra Rifle and the "heavies" if you've had any experience with them.
Thanks, :-)