I haven't shot the Sec9 too much lately, because of the heat here in Texas. 112 yesterday and 114 the day before. But the old Sec9 has gone over 2,500 rounds without a malfunction of any kind, with brass or aluminum cases. Have had a few failures to eject with some steel case. I have been shooting for over 50 years and this is the most reliable pistol I have ever owned. Well, maybe my dad's old Colt Woodsman never malfunctioned, but I never tried to put aluminum or steel case ammo thru it.