I have had a FTF/Jam issue. The gun would cycle after firing but then it wouldn't fire. The slide would seem to be in battery, but stuck; can't rack it without considerable force pulling it back. This happened three times while using two boxes of Fiocchi 115 gr. FMJ ammo. I did not have this problem with Federal, Winchester or Remington.
Had the exact same issue using Armscor 124gr FMJ on my P10S, and only that brand, more upscale brands worked fine. After about 200 rounds, the barrel became more forgiving, less FTFs. Still, I bought an ammo gauge so I wouldn't have to disassemble my P10 every time I got a new box of ammo.
Yes, I gauge every single box of ammo I buy now. In practice, the ammo gauge seems a little more exacting than my barrel, so that's good.
I just bought a box of SIG 124gr FMJs. I'm happy to say all the rounds passed the ammo gauge.
A recommendation was made earlier for Blaser Brass ammo. I second that recommendation. Best quality ammo for the money I have found.
I've got some Fiocchi ammo, Black Mambas and their EMB ammo. Thankfully, they gauged/plunked well.
Hope you enjoy your P01