Explain this one.

[tv1217]

I had been having feed issues with my Mosin Nagant M44. It would catch up when I loaded the magazine to 5, either one by one or with stripper clips. I swapped what is apparently called the interrupter assembly with the one in my 91/30. This sorta fixed the issue, but it still jammed up more than I would have liked. I then swapped the bottom spring in the magazine and bam, it works smooth now. Now here's the weird part. You'd think the 91/30 would now have the problem that the M44 was having with it's parts in there, but no, it still works fine.