PM9 feed ramp

[genebert]

I've got 300 rounds through my PM9 now and was getting an occasional failure to return to battery. Noticed the feed ramp was a little rough and thought that a little polishing might cure the problem. I went to polish my feed ramp with a Dremel tool last night and noticed something. The ridge at the top of the "U" on the right side of the feed ramp is low, shallow and smooth while the ridge on the left side is much higher and steeper. The feed ramp is more like a backwards "J" than a "U." Is this normal? I don't know how to explain it any better than that. Any advice would be appreciated.

[warmrain]

Originally posted by genebert
I've got 300 rounds through my PM9 now and was getting an occasional failure to return to battery. Noticed the feed ramp was a little rough and thought that a little polishing might cure the problem. I went to polish my feed ramp with a Dremel tool last night and noticed something. The ridge at the top of the "U" on the right side of the feed ramp is low, shallow and smooth while the ridge on the left side is much higher and steeper. The feed ramp is more like a backwards "J" than a "U." Is this normal? I don't know how to explain it any better than that. Any advice would be appreciated.
Most important advice: "Sir, step away from the Dremel tool!".

Seriously, there is no problem on a firearm that cannot be made worse with a Dremel tool.

Second piece of advice: If the pistol was running fine and the FTRB is new... it has nothing to do with the feed ramp. Though polishing it may help, it may also mask the problem.

Was the pistol running fine before? If yes, the something else has changed.

The "J" shape is the design. The ramp is off center. This is one of the secrets to their small design.

Best, Cars

P.S. IF you really want to polish the feed ramp let me know if you want IMHO the best way. Gotta run!

[Dandapani]

1) Maintain good lubrication on the barrel and barrel hood. I used to use Tetra Gun Grease that wasn't easily cooked off a hot barrel.

and

2) What color is your recoil spring? Silver or black? The new design is black.

[Kahr-mengia]

Warmrain

"P.S. IF you really want to polish the feed ramp let me know if you want IMHO the best way. Gotta run!"

I'd like to hear your thoughts on this subject please.

Best to all,
Kahr-mengia

[warmrain]

Originally posted by Kahr-mengia
Warmrain

"P.S. IF you really want to polish the feed ramp let me know if you want IMHO the best way. Gotta run!"

I'd like to hear your thoughts on this subject please.

Best to all,
Kahr-mengia
There have been many pistols ruined by ramp polishing and throating; and many ruined by the Dremel tool. The combination can be fatal.

Esp. since the Kahr pistols are so easily and quickly done by hand...

Here's the deal: the machining is done with a cutter that move horizontally. You want to polish out those machine marks and the best way to do that is vertically. Additionally IF you left any marks of your own (doubtful) they would be in the same direction of the bullet's travel... and this is why the existing marks can be an impediment to JHP feeding.

Check for an empty pistol and disassemble.

I use 1000 grit paper and a rubber eraser that either closely matches the shape of the feed ramp's curve or I cut one from a big red eraser. I then cut some strips of 1000 grit paper about as wide as the feed ramp and about twice as high and place the paper face down on the ramp and push it up and down with the eraser.

The eraser is sticky enough to move the paper and firm enough to do the job while still plyable enough to not change the shape of the feed ramp. Not changing the shape is crucial.

polish up and down and check often for desired results. Do not extend into the chamber more than about 10% of the total number of up/down strokes if at all... When it looks really good then put some oil on the wet and dry 1000 grit and go a little more. Then finish with some metal polish like Flitz and it will look like chrome.

You can do this while holding the barrel in your weak hand wit the muzzle resting on a soft but firm surface...

[warmrain]

P.S. This should take no longer than about 30 minutes... Maybe 45-60 minutes if you are going real slow and sipping a cocktail during the process...

Go slow, check often. Only remove enough to get rid of the machining marks. If the marks are severe you should not try and remove them all, just about 80%.

[Kahr-mengia]

Warmrain,


Thanks for the tip.

Kahr-mengia

[genebert]

The "J" shape is the design. The ramp is off center. This is one of the secrets to their small design.

That's what I needed to know. I didn't get carried away with the Dremel. Used soft felt with a tiny bit of Flitz to just remove the horizontal striations on the ramp. Didn't do any throating or contouring. I'll let you guys know how it works.

Thanks for the tips and the help!

[warmrain]

Originally posted by genebert
That's what I needed to know. I didn't get carried away with the Dremel. Used soft felt with a tiny bit of Flitz to just remove the horizontal striations on the ramp. Didn't do any throating or contouring. I'll let you guys know how it works.

Thanks for the tips and the help!
If you have to use a Dremel, that is the best method, felt and metal polish. It's better if it can be done with the polishing motion up and down if that is possible.

Yes the design... the trigger bar takes up some room on one side and they found a way to narrow the pistol and get the bore axis lower with relation to the drip by "moving" the feed ramp to the other side from the trigger bar (this is how I remember it). It is described on the web somewhere, perhaps even on the Kahr site.

It's pretty cool really...