Failure to Feed - fully

[cananian]

I have a PM40 that I purchased used. About one out of 10 times, the cartridge doesn't feed fully into the barrel. It typically lacks about an 1/8 inch from fully seating.

The failure doesn't occur predictably - its not the first or the last bullet in the mag. The failure doesn't occur with any specific mag either.

I have replaced the recoil spring and guide assembly but this doesn't seem to have eliminated the problem.

When I extract the bullet that failed to feed, I have noticed a small "dent" or "gouge" mark on the bullet head. Typically on the edge of the bullet head.

Any ideas on what is going on?

[jocko]

have u tried polishing the feed ramp and inside the chamber to smooth things out even more. this seems to help alot. that ding is the bullet either hitting the front of the magazine upon recoil or hitting the bottom of the feed ramp upon recoil.

Are u having to bump that round into the chamber when it hangs up?

pm sent

have u, yourself given this gun a 200 round break in yet?? It just might needs more rounds down range also...

[cananian]

I've looked pretty hard at the feed ramp but I haven't tried to polish - I'll give that a shot.

I do end up bumping the round into the chamber when I notice it, but most of the time I simply pull the trigger and it doesn't fire.

I have run about 200 rounds through it at this point. After the first 100 I replaced the springs.

I'll do some polishing and see what happens. Thanks

[cananian]

Just for information for anyone facing this type of problem - I think I have it solved.

I had replaced the recoil assembly on this gun with Kahr parts and it didn't solve the problem.

I ordered some springs from Wolf Gun Springs - the heavier set designed for the PM 40. After installing these heavier recoil springs, the gun fired without a glitch. Fed 100 rounds through it without a problem.

Clearly, brute force won out on this one. I'll still try polishing the ramp but it's now working reliably!:)

[Jim K]

Check out the following link:

Pistolsmith.Com • View topic - K9 extractor tension (http://www.pistolsmith.com/viewtopic.php?t=10806)

There is more info on this problem elsewhere on this forum.
A 20# spring from Wolf helped my P9 but the real fix was to lower extractor tension.

I found that there was at least one person who protested but offer no useful info. Ignore the naysayers and wannabees.

Good luck and let us know how things work out down the line.

aDios, Jim K

[LDM]

When Ned Christiansen talks, I listen.

The reference in Cylinder & Slide's Kahr packages to "adjust extractor tension" is another clue. Those folks know which end is the muzzle and which is the butt.

A Kahr is an elegant and sophisticated system.

I have spent a good bit of time with 1911's over the years. Know enough to know I don't know it all by a wide measure. The 1911 is a much simpler and robust system from another time. And that is not a criticism. But a 1911 will choke on excessive extractor tension in a heartbeat.

The idea that excessive extractor tension might be a problem is a valid point that should to be in the set of potential solutions when problems occur.

Stay safe.

[jocko]

just for information for anyone facing this type of problem - i think i have it solved.

I had replaced the recoil assembly on this gun with kahr parts and it didn't solve the problem.

I ordered some springs from wolf gun springs - the heavier set designed for the pm 40. After installing these heavier recoil springs, the gun fired without a glitch. Fed 100 rounds through it without a problem.

Clearly, brute force won out on this one. I'll still try polishing the ramp but it's now working reliably!:)

with the heavier recoil springs.

[mtmag]

I had a similar problem with my P40. I found the problem to be that the slide lock, that holds the slide open when the magazine is empty, was the problem. When the bullet fed up from the magazine, some brands of ammo were a little longer, or a different shape, and the side of the bullet was hitting the slide stop.

Sometimes the slide would lock open. But other times the bullet would feed but would not go completely into battery.

I filed a small bit off the end of the slide stop so it no longer hits the end of the bullet and it works fine.

Lock your slide open and insert a mag and you can often see the bullet hitting the slide stop as it goes into feeding position.