The only magazine springs I've actually seen set was a batch of early Korean War manufactuer M1 Carbine 30 rounders, a post Korean War M1 Garand that had been stored loaded for 45 year (!!!!!!), and a couple of pocket pistols (.25 caliber Euro-trash of questionable pedigree, either Spanish or Portugese) from the 20s or 30s. But I rotate just to be sure. Finding out the hard way doesn't happen on the range. <br><br>Full capacity is another issue, mostly having to do with magazine design. I don't think anyone knows for sure what cuases it, other than crud in your mags. The early 20 rounds for the M-16 and 30-32 round mags for a lot of SMGs are notorous for this, but I've also seen it several times in Beretta magazines. In fact, I know of one M92 mag so gummed up by lint and dust (carried in the Bianchi mag pouch, in the Kuwait area, during a dust storm) that it had to have the baseplate pulled off just to get the rounds out! That is the worst M9 story I've heard, but I've heard a lot of them. The Sig, S&W double stacks, Glock and Browning all have similiar reports, but nowhere as bad as that one with the M9. Actually, about the only double stack mags that I've never heard of having this problem are H&K, the AK and the WWII Russian SMGs, but that doesn't suprise me. <br><br>The Brits load thier 13 round Browning mags with 10 rounds, and they find that there is no problem no matter how bad the dust is. My Bowning has gotten submerged in a few swamps and marshes, and I've had a couple of mags that needed to be cleaned before they fed right. But if I was carrying 12 rounds, they later ejected thier rounds just fine when I thumbed them out. <br><br>The same kind of shorting solved the problems with 20 and 30 round M-16 magazines, the FAL mags, and the various SMGs. It's probably bad engineering with those, becuase I heard some tales about them being screwed up on the range using fresh from the manufacturer magazines when they were full loaded. <br><br>My rule of thumb has become to load double stacks short by this formula:<br> (capacity - 10)/10<br><br>It means that 12-20 round mags get loaded with one less, 30 rounds two less, et al. Less ammo, yes, but if it can't be solved with 10 rounds or less, and you are civilian, you probably made a bad call someplace. 99% of the time, with a pistol, you won't see it. It's that 1% that reminds you that Murphy has a sense of humor, and it is your turn to the be the butt of the joke.<br><br>Single stacks don't have the problem with crud, becuase the rounds don't roll against eachother as much.<br><br>A bigger problem is bad ammo profiles that your feed ramp doesn't like. That's why I recommend shooting a couple boxes straight of any new ammo before you trust it totally.<br>