hi Sieger, When measuring the MP mag follower springs... I had two that were as new, no set, full tension... and 2 that had appearantly taken a full set... probably 10% less then the "as new" springs... and finally, 1 in-between the two sets... The two as new springs were tough to load under even the best of circumstances... and the other three, just slightly less so... I used a tool, but with the extreme tension, it was a clumsy, drop your items type of exercise!!
The plastic based mags can't stand too much clumsy.... but, all 5 worked well whether new or old "strong" springs... which leads me to believe a slightly less strength spring, (yet stronger then pre 45 P.08's) would possibly be sufficient to allow for 100% function, and, still be enjoyable to shoot... Now, that being said, I had a 1970's Mauser parabellum in the P.08 style, 4" bbl.. and it worked equally well with any & all mags I put thru it?? But If I have to have that strong of a mag spring to make my luger work, I'm look'en for a different luger!!
best to all, til...lat'r....GT