Learned some good lessons via Underwood.
I bought a glock 20 and wanting to get the most out of it, I ordered Underwood's full power loads (as opposed to the light loaded 10mm, giving .40S&W velocities everyone else is marketing).
. Now don't get me wrong, i love glocks and i respect the 10mm, but for me, the two didn't go well together. There's just not enough mass in a glock to shoot 10mm comfortably. I'm sure a 1911 frame would be a hoot.
Nevertheless, after six rounds, i took it up front and traded it for a 9mm Sig ;-)