I began having problems with my Kahr MK40 not feeding problem.  The round would get stuck and lock up the pistol.

I have a bad right hand and thought that I wasn't gripping the gun properly but the last time out I checked it and decided that wasn't the problem.

I got the pistol home and checked the feeding by hand.  That wasn't easy with a bad hand and the 100 pound recoil spring on that little bugger.

It looked as if the round was getting hung up trying to get into the chamber so I tried dropping a round into the chamber rather than feeding from the magazine.  It wouldn't go!

All of my reloaded rounds are checked in a Dillon gauge before they go into the ammo box.  They all passed.

I grabbed the calipers and measured the case mouth and the case just below the flare.  The case mouth was .002"-.003" larger.

I set up the crimp die and adjusted the crimp to be the same as the case below the flare.  I hand checked the feeding from the magazine.  It worked!

These cases had all passed the Dillon case gauge but would not feed into the Kahr chamber.  That must be one tight SOB.

Just remember sometimes close is not good enough.

Some chambers are tighter than others, fortunately...

I would remove the bbl from the gun before chamber testing

It may not be crimp at all.

We shot several 9mm pistols today. Glock, 2 different Ruger (same model) just to name a few. My 102gr Lee cast round nose worked great in all but one.

That one was a Kimber compact. The first round chambered with a little help the next would not go into battery and locked up the slide solid. We had to put the slide in a padded vise to get the action open.

We stripped the pistol down and sure enough this particular loading failed the "plunk test" in this particular pistol.

The bullet was engaging the rifling before the round was fully chambered. So for this pistol I will need to shorten the OAL until it passes the plunk test.

The 124gr Truncated Cone bullets worked in all the guns as did the 100gr plated. The 100gr plated were the exact same OAL as the Lee 102gr and both are round nose but the nose profile is slightly different allowing the plated to work fine.

I suggest you check for this same condition with your ammo.

Motor

Failed the plunk test as loaded.  After reducing the crimp passed the plunk test.  Not the bullet.

Sorry but that doesn't make any sense at all. Unless if you mean "reducing" as in crimped more reducing the case diameter at the mouth.

If this is correct you didn't reduce the crimp you increased it.

Motor