I have the PX4 Sub compact in .40 S&W. No issues at all. Right out of the box it fed and functioned perfectly. It ate every brand of ammo and fed hollow points without a hitch. I carry this in the warmer weather when it is more difficult to conceal a full size .45 ACP. I use a Comp-Tac IWB holster and it is a tuckable holster.