I'm certainly no expert, but I've found that some gun designs will tolerate a wider variance in mag-spring pressure than others. I'm perty-sure that that has to do with timing relative to exactly when/where the top round is sitting as the breach block (or bolt) moves into the position which is supposed to strip it from the magazine.
Examples of what I'm trying to say would be my "as issued" 1911A1 and BHP, both of which run equally well whether they are being fed from an old mag which has a relatively weak mag-spring, or from a shiny new mag with a noticeably stronger spring.
On the other hand, I know from experience that a weak clip-ejector spring will cause feeding issues in a an M1 Rifle due to the fact that the top round aint always where it's supposed to be WHEN it is supposed to be there. Same thing with my Mini-14, meaning that I've got an old factory 20-rd mag that got so "weak" over the years that it started giving me feed issues...UNTILL...I reduced the volume of the gun's gas system which in turn, reduced the speed of the op-rod/bolt, which in turn gave the weakened mag-spring plenty-enough time to move the top round into it's correct position.
Yeah, I'm perty-sure that it's all related to "time 'n distance", or as I like to put it...timing...and like I said, some gun designs seem to be more tolerant in that aspect than others. Hence the different experiences we see being related by folks with different guns.
Like I said though, I'm certainly no expert. All I know is what I know.
DGW