There are 2 areas of concern in my mind for the little Kahr pistols.
First, these little guns are rated for +P+ loads; that means they have a ferocious stout recoil spring. In a FTF malfunction, is the load stout enough???
Second, they are small, as "serious" caliber guns go, and, accordingly, despite an attempt to increase slide mass on the '40's, have a really short cycle time, which means the magazine spring must also be really stout, to get the round up into position in time to be picked up and fed. Particularly if the FTF malfunction increases with the number of rounds in the mag, look at the mag spring critically; if weak, that could be the problem.
My MK9, a SS pre production gun, was evidently hand fitted, judging by the (excellent) trigger, and has yet to fail to feed or function in any fashion; It has maybe 1500 rds down the pipe.
As a type, they lack second strike capability, which is probably a good thing, unless you lack the digital strength for an immediate action drill (tap-rack-bang); in which case, pick a different gun.
Hope this helps, Terry
Don't start no s**t and there won't be none, Terry