Glock G35 slide locking back !

[katana_1127]

I have exactly the same problem as "RECON" with his 10mm, I have a gen 3 Glock G35 in .40S&W that locks the slide back with rounds still in the mag when shooting factory 180g Winchester or 165g ammo.
Where should I start ? Any help will be appreciated.
Best regards,
Rob
katana_1127@hotmail.com

 

[SDC]

There are two common causes for this;
one: you've got the pistol incorrectly assembled, with the slide-stop spring on the wrong side of one of the locking-block pins (if it doesn't happen when you cycle the slide on the empty pistol slowly by hand, then it's likely problem two);
two: your grip on the pistol is such that one of your fingers is bumping the slide-stop up during recoil (check for this by firing the pistol one-handed, with your thumb low on the grip).