Paddlingcamper said:
I called the FN Pro Shop about that and they said that this was a duty gun and intended for LE Type ammo and not 115gr cheap stuff. The gun likes at least 124gr. or bigger to cycle properly.
That doesn't make sense. 124 gr. ammo is just heavier... and that can actually slow things down. As does 147 gr. It's the LOAD that matter. LE type ammo can include a variety of 115 gr. ammos, and the military (including much of NATO and the U.S. DoD) uses both 115 gr. and 124 gr.ammo -- and even hotter versions of both for sub-machine guns. The standard NATO ammo is loaded a bit hotter than standard civilian factory ammo, but not to the +P range. Cheap 115 gr. ammo
IS often under-powered, but that isn't true of all 115 gr. ammo. And 124 gr. ammo won't necessarily cycle better just because it's 124 gr. (We're talking about bullet weight, not the powder loads driving those bullets!) Good quality 115 gr. should work fine.
Increasingly, I buy range ammo in bulk, and that gives me good quality ammo at a price that matches or beats the cheapest 115gr. stuff (such as Winchester White box, which I've never really liked.)
Paddlingcamper said:
... I was also told by one guy that he caused this to happen himself by resting his thumb against the slide lock lever.
I wonder if that "one guy" had a "safety-equipped" gun and was letting his thumb rest against the safety
AND slide at the same time, or was just letting his thumb rub against the slide? That will definitely slow the slide's movement and cause problems -- even with top-quality (hotter, too) ammo. (Most folks thumbs won't rest that easily on the
slide stop lever while firing.)