On my 50,000 s/n range Inland the spring or flipper is rusted to the point that it would flop around... I cut a .010" piece of shim stock & shimmed it.. The shim doesn't show so it's OK by me & good enough because it's a ratty but all Inland coded carbine that makes a dandy, looks like it's been in a war carbine. Just saying a thin little spring can get rusted and need replaced..