New PM45 Range Test

[wyntrout]

I found the reason for the "crunch". After after comparing PM45 parts to their PM9 counterparts and screwing with a lot of the parts of the PM45 that I shouldn't have, I tried sticking loaded magazines in each and trying to see a difference. I found a big one. Look at the first 2 photos #43 and #48. These are of the PM9 with a loaded magazine inserted. Notice that there is about 3/16" between the rear of the cartridge and the striker housing and the lower ridge of the slide that strips the rounds off the magazine as the slide returns to battery position.
Now look at the next 2 photos of the PM45 with a loaded magazine inserted and locked in place. There is NO clearance and the ramp/stripper/striker housing is resting on top of the base rim of the cartridge. This is why when the slide is released the stripper rides over the cartridge pushing it back down into the magazine and you have an empty chamber and a scratch on top of the cartridge. The magazine IS locked into place, but by squeezing the top of the slide and the bottom of the magazine hard enough the stripper mashes the rim which gives enough that cartridge is pushed forward of the stripper. That was the "crunching" sound.
Clearly something is wrong here. Both pistols have the slide locked to the rear and there is a big difference in the gap on the PM9, or lack of one in the PM45.
You guys with PM45s please look and see if there is a gap in your pistol between the rear of the cartridge and the stripper/striker housing. This is a big flaw and I think the magazine well is too far aft at the top or some other things are wrong. This sucks!
Wynn

I added a 5th photo of the top round in a magazine which gets scraped as the "stripper" rides over it. This happened a lot.

[jeep45238]

Wyn, all of my pistols, regardless of make, model, or caliber, have the slide go beyond the rim of the case when it's in the mag. Some by only a little, others by over 1/2 an inch.

It's impossible to feed from the mag if the (technical name I can't think of) part of slide that sticks down centerline of the mag can't get behind the back of the case - the further this distance, generally the less finiky the gun is. I'd be boxing it up and shipping it out on Monday with those pictures.

[wyntrout]

I had a lot of chores and other things to do and I finally got around to finishing cleaning the two guns for the range trip yesterday. I have been comparing all of the parts and how things look when assembled and screwed with the ejector trying to make the PM45 one look more like the PM9, thinking that was depressing the rear of the cartridges too much. I had an oopsie with my "Dremel-Like" tool but nothing major. I hope that doesn't void my warranty or something. Then I tried loaded mags with the slides locked back and seeing if I could find any differences. I couldn't believe the difference and I can see how it's screwed up now and why the magazine could be locked in place and no round being stripped. I saw the scratches on the tops of the cartridges in the magazine after failure to chamber a round. The squeezing I did caused the rim of the cartridge to fail enough to let the "stripper" slide behind the cartridge base and then the round could chamber.
I guess that I can't be lucky with everything. At least I have my PM9 as my main carry, anyhow. I guess that I shouldn't have mocked Murphy the other day, either!
As an emergency measure, I could very slightly round the bottom of the "stripper" but that might screw something else up. This isn't an emergency, though.
At least I figured out the problem. How they will fix that, I don't know. This is really weird -- the way there's no gap at all! I wonder how many other guns have this problem.
Wynn

I forgot to add something kind of funny. I forgot to take a cap in with me, but I did get some shooting glasses -- cheap Remington ones $4.95 at Wally World, but they are great. The yellow lenses help and I could see the sights and the target better. Using my prescription progressive lenses made one or the other out of focus.
Another thing is that I took a LOT of hits to the forehead from ejected cases... I mean sometimes it was like every one of those suckers came back and boinked me in the middle of my forehead. After the range, I went to Sam's Club and shopped there for maybe a half hour. When I got home, I finally saw my forehead and there were 7 or 8 or more little black marks from the ejected shells! My wife thought that was funny when I told her later.
The time before last I did take a cap, but I left it in the car and tried to duck when I could see them coming... to no avail. I could blink but that was about all I had time for. Sometimes the things bounced off part of the motorized target apparatus overhead the station. NOTE: Remember CAP!

[jeep45238]

As an emergency measure, I could very slightly round the bottom of the "stripper" but that might screw something else up. This isn't an emergency, though.

Actually, that would make the problem worse. It would drive the cartridge down into the magazine.

[wyntrout]

I think that it would just push the cartridge forward enough to scoot behind like when the rim gives way with my "squeeze" -- the "crunch".
I tried "tapping" the top rear corners of one magazine with a small hammer, but that's tough metal and it wouldn't deform inward to push the cartridge forward a bit.
<Sigh> I'll have to email Ian at Kahr and see if they will pick up the tab for shipping.
Wynn

Hmmm. If I bevel the bottom of the cartridge rim that might solve the problem... for one round. I want to hear from some other PM45 owners and see what kind of gap they have or if they are having problems, too.

[jeep45238]

I think that it would just push the cartridge forward enough to scoot behind like when the rim gives way with my "squeeze" -- the "crunch".

The only way to modify your gun to feed would be to grind in a rearward angle on the breech face, starting right below where a round would sit when in battery and extending rearward just enough to consistently clear the rim of the cartridge.

I may know a thing or two about mechanical interfaces - I optimize repair processes for jet engine parts, and have built some quick cars with little tolerance stackup throughout. My spelling and grammar are horrible though



Putting a bevel on the edge will do nothing except have the slide touch less of the rim on the cartridge face

[wyntrout]

I can't wait to see what the fix is -- a redesigned frame, moving the magazine well forward at the top.?
Wifey's home so I must get ready to entertain her. I just had my buddy over to help me get the new-in-January 58" Samsung plasma HDTV, top-rated by Consumer Reports... best HDTV rating of any TV -- off the damn wall and remount it to the stand so the repairman can get at it tomorrow. It really sucked unhooking about 9 or so electronic components, UPS's, cables, power cords... just lots of stuff and move the heavy cabinet holding all of that stuff. I just hope it can be fixed ASAP. I'm tired of using my little 22" LCD HDTV -- it just ain't the same.
Hmmm. My new TV blew up -- loud crack like a firecracker. My new PM45 is broken or defective... what else is going to happen?? I shouldn't have mocked Murphy the other day!
Wynn

[Bawanna]

I see the most important tool is at the forefront. The BFH. Thing looks fast just settin there don't it.

[gb6491]

...
As an emergency measure, I could very slightly round the bottom of the "stripper" but that might screw something else up. This isn't an emergency, though....

Actually, that's sort of what I did to fix the same problem (actually, I could not get my magazine to seat) with my CW45. I slightly changed the angle that the slide is beveled to where the rim of the round contacts it.
In the photo below, I stoned the bevel so that the tailing edge of it is moved further rearward (red arrow). I did not change the starting point of the bevel (green line).

The round in the magazine now cams/rocks forward into place, ready to be stripped out of the magazine. In the photo below, the shot on the left was taken just as the round contacts the slide; on the right, shows the magazine seated:

A quick movie of the action:
YouTube - slidemod.MPG
Regards,
Greg

[Bawanna]

That looks like a good fix. Your's obviously is showing no gap at the rear just like Mr. Wyn mentioned. Seems like if it was mine, I'd want Kahr to do what you did unless I picked up a used one with issues. Kahr should have caught that easy.