When Federal Ammunition introduces a product like Federal Champion 115-gr FMJ 9mm ammo to the USA market, the lowest powered ammo ever offered, then it is an ammo issue. It won't function in a new Gen4, New XD or New Kimber. Champion would not even function in my Gen2 G19 when I installed a brand new factory recoil spring assembly to test. With it's latest 9mm offering, Kimber recommends only 124-gr and higher full power service ammo. Sometimes it is an ammo issue. Sometimes it is a shooter issue. Sometimes it is a recoil spring issue. Try not to forget all the issues stated here that new shooters have had after buying a Gen2 or Gen3 "C" model 9mm Glock.