I posted a question on the Rifle forum:
http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=265002#Post265002

I know that Nagant modified at least one Remington patent. Back then, you did not have to acknowledge previous patents by others as you do today.

Mike,

I would think the issue is one of back pressure. It appears to be more of a falling block.

Pete