Bah! Mods please move to the correct section. I thought I was there when I made the post.
Sorry
I'm under the impression that a loaded mag will not weaken a spring. The repetitive loading and unloading of the spring is what i've always been told will weaken them over time.why take a chance on weakening the spring
if you can't hit your target with 28, i'm sure the other 2 wont help
mrpski agrees with this assessment being the same sort of old timerThose of us who are old timers that carried M-16 & varients in Vietnam learned to download our mags. a round or two back then to make sure that it would feed reliably. The mags. of that time tended to double feed or jam the bolt by not coming out of the mag. right if they were filled all the way up.
These days with the better springs and anti-tilt followers in the modern mags., you're probably good-to-go and have found it to be so, but old habits die hard.
BTW, I still only put 28 in my 30's just to make sure.