These are the longest I've seen... from the 8-rounders, but the springs are the same, supposedly, for the 7-8 round 9mm & .40 mags.

You can see that the springs are twice as long as the tubes. These are new mags with springs uncompressed by loading with bullets. I've never had to resort to using nails and pins with Kahr mags. I just compress and push the springs in with my strong hand while taking up and holding with the thumb of my weak hand, with my weak hand holding the tube pointing away from me.
Wynn
USAF Retired '88, NRA Life Member. Wife USAF Retired '96
Avatar: Wynn re-enlists his wife Desiree, circa 1988 Loring AFB, ME. 42nd BMW, Heavy (SAC) B-52G's
Frédéric Bastiat’s essay, The Law: http://mises.org/books/thelaw.pdf
Thomas Jefferson said
“A government big enough to give you everything you want, is strong enough to take everything you have.”
and
"Peace is that brief glorious moment in history when everybody stands around reloading".