My turn ...

[DavidR]

After 700+ rounds thru my CM9 using 2 mags, I broke a follower. Didn't notice it until I got home from the range so I'm sure the mag still works. Sent an email to Kahr asking for a new one. Funny thing is I just bought a 3rd mag last week.

http://i32.photobucket.com/albums/d33/David-R/A8BFBA6B-83EE-48DA-B00B-F5A5617FA25C_zpsmjsxsrhb.jpg (http://s32.photobucket.com/user/David-R/media/A8BFBA6B-83EE-48DA-B00B-F5A5617FA25C_zpsmjsxsrhb.jpg.html)

[C0untZer0]

:frown:

[DavidR]

Heard from Eoin. They will send out a new follower this time, another break will require a trip back to Kahr.

I recently started using an o-ring at the bottom of the mag to eliminate that nasty Kahr pinch. Any chance that could be the cause of the break?

[C0untZer0]

The root cause is that the feed ramp butts up against the magazine follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule. It doesn't change the fact that the feed ramp extends too far back into the magwell.

[DavidR]

The root cause is that the feed ramp butts up against the magazine follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule. It doesn't change the fact that the feed ramp extends too far back into the magwell.

Yes, I agree that's the problem, just wondering why the follower didn't break earlier.

[C0untZer0]

Did you try different ammo? Something that would have a different recoil impulse than stuff you were shooting previously?

[DavidR]

Did you try different ammo? Something that would have a different recoil impulse than stuff you were shooting previously?

I did - 1 mag of Federal HST 124 grain. My normal carry ammo has been Speer Gold Dot 124 and I've previously fired a bunch of different 115 and 123 FMJ.

[340pd]

In my world, if the gun manufacturer says it is 9mm, it should shoot virtually all the commercially available 9mm ball ammo. Any gun I have retained in my collection will reliably feed anything I choose to put in the chamber or out it goes. The only exclusion to this, is the retention of my .32 Seecamp, which now has at least a half dozen commercially available rounds that are reliable and accurate. Although it is fired infrequently, it has yet failed to cycle or feed.

[DavidR]

In my world, if the gun manufacturer says it is 9mm, it should shoot virtually all the commercially available 9mm ball ammo. Any gun I have retained in my collection will reliably feed anything I choose to put in the chamber or out it goes. The only exclusion to this, is the retention of my .32 Seecamp, which now has at least a half dozen commercially available rounds that are reliable and accurate. Although it is fired infrequently, it has yet failed to cycle or feed.

Thankfully I've never had a problem feeding, firing or ejecting any 9mm I've tried.

[berettabone]

The root cause is that the feed ramp butts up against the magazine follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule. It doesn't change the fact that the feed ramp extends too far back into the magwell.

I would tend to agree with this............the follower sits so close that any change can be a problem.

[jocko]

I believe the Rohrbaughg is very ammo specific to, along with Kimbers solo memo that u should shoot only +P ammo for reliability. As l;ong as a person goes into that buy of that particul gun with knowledege of this, he has zero complaints after that..Just sayin

[DavidR]

I would tend to agree with this............the follower sits so close that any change can be a problem.

I liked the o-ring because it eliminated the pinch but I have a possible alternative solution. I put the base plate from a CW9 mag on the CM9. It fits perfectly and fills in the gap that causes the pinch. I then sanded down the ridge on the CW9 plate and I can get a 3-fingered grip (most of my pinky).

http://i32.photobucket.com/albums/d33/David-R/9caa6d96-b08b-4371-9931-b0a54aa70585_zpsb3e58ed7.jpg (http://s32.photobucket.com/user/David-R/media/9caa6d96-b08b-4371-9931-b0a54aa70585_zpsb3e58ed7.jpg.html)

(http://s32.photobucket.com/user/David-R/media/95C740C0-B31B-4665-95D5-F1A6D51CBAB7_zpsfjtbp0tc.jpg.html)

[DavidR]

Fired several mags with both my good mags today without the o-ring and no broken followers. I'll keep an eye on things but the o-ring is potentially the culprit.

[Tpsfoto]

And here is mine just as today, I had no clue it was broken, just decided after a shooting class to clean all my mags. I did not use this one today.....but found it broken when I removed the ammo from the loaded mag. I just sent to Kahr an email to service and sales with the photo......do you think I have to go further to get a replacement?
http://i31.photobucket.com/albums/c381/tpsfoto/290b7233-492e-4843-99c2-2b5054183050_zps731dbd30.jpg

[DavidR]

They sent me a replacement immediately. Eoin at Kahr said that if it happens again they will need to see the gun.

[MBSL500]

They sent me a replacement immediately. Eoin at Kahr said that if it happens again they will need to see the gun.

You can count on it happening again..... and you'll have to send your gun back to them.

[DavidR]

You can count on it happening again..... and you'll have to send your gun back to them.

It hasn't happened again, yet. It may have been caused by my using an o-ring to fill in the space between the magazine and the gun that was causing a "pinky pinch".

[codegeek]

It hasn't happened again, yet. It may have been caused by my using an o-ring to fill in the space between the magazine and the gun that was causing a "pinky pinch".

It's not the O-ring. Broken followers are a known problem with Kahrs. Eventually, you will need a rampectomy.

Sent from my SM-P600 using Tapatalk

[C0untZer0]

In your OP you said you had 700 rounds through the gun before it broke a follower. I was wondering if it was possible that you broke your first follower earlier on but just didn't notice it?

If you really did get 700 rounds through without breaking the follower then maybe the feed ramp is back far enough where it doesn't usually contact the follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule, but it may be enough that the ramp starts tapping the follower.

I should have taken before and after pictures of my feed ramp. Kahr REALLY shortened it. They weren't just gradually polishing it down until there was enough clearance - they weren't fooling around, it is a BIG difference.

[MBSL500]

In your OP you said you had 700 rounds through the gun before it broke a follower. I was wondering if it was possible that you broke your first follower earlier on but just didn't notice it?

If you really did get 700 rounds through without breaking the follower then maybe the feed ramp is back far enough where it doesn't usually contact the follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule, but it may be enough that the ramp starts tapping the follower.

I should have taken before and after pictures of my feed ramp. Kahr REALLY shortened it. They weren't just gradually polishing it down until there was enough clearance - they weren't fooling around, it is a BIG difference.

Can you post a picture of the feed ramp "after"?

[DavidR]

In your OP you said you had 700 rounds through the gun before it broke a follower. I was wondering if it was possible that you broke your first follower earlier on but just didn't notice it?

If you really did get 700 rounds through without breaking the follower then maybe the feed ramp is back far enough where it doesn't usually contact the follower. The o-ring might be exerting a tiny amount of pressure to move the magazine slightly forward - the distance would have to be miniscule, but it may be enough that the ramp starts tapping the follower.
.

There's no chance that the follower broke before 700 rounds. I clean my gun and mags after every session.

I can't say for sure it was the o-ring but it broke shortly after installing the o- ring. I've been to the range once since removing the o- rings and followers were fine.

[MBSL500]

There's no chance that the follower broke before 700 rounds. I clean my gun and mags after every session.

I can't say for sure it was the o-ring but it broke shortly after installing the o- ring. I've been to the range once since removing the o- rings and followers were fine.

Wishful thinking. :)

The O-Ring and the broken follower will prove to be unrelated.
There are FAR too many who have had broken followers who never installed an O-Ring.
It's probably best just to get your shipping box labeled and gun ready to send back.

[DavidR]

50 rounds through the CM9 last night, one mag, follower fine. I still think it was the o-ring.


Dave

[mmncw]

Could've been the o-ring. It might have taken away the last little bit of slop in the magazine fit, leading to impact or harder impact with the ramp.

[muggsy]

It's kinda like the Chinese water torture. The feed ramp continues to give the follower just a bit of a bump, but over time the plastic becomes work hardened and brittle. Sooner or later something has to give. The damage is cumulative. The hotter the ammo the sooner the failure. Muggsy has spoken.

[skiflydive]

The hotter the ammo the sooner the failure. Muggsy has spoken.

Agreed! I broke one follower last year firing 124 gr NATO rounds so I believe what Muggs says here is true. After reading all the "Rampectomy" posts I shaved about .020 off the very back edge of the ramp using an abrasive polishing wheel on a pedestal grinder we have here at work. I was very careful to follow the arc, angle, and scratch pattern of the original profile. Comparing it to another CM9 you can't see any difference...ie, it doesn't look like I hacked it off with a Dremel or a grinding wheel. Testing the way others recommend the ramp doesn't contact the follower anymore at all. I haven't had any follower issues since, but then again I haven't fired any more of those NATO loads.

2 things...I'm not recommending anyone else do a rampectomy like this - just explaining what I did. Second, I wonder how many followers have failed for people using hotter or +P ammo

[DavidR]

It's kinda like the Chinese water torture. The feed ramp continues to give the follower just a bit of a bump, but over time the plastic becomes work hardened and brittle. Sooner or later something has to give. The damage is cumulative. The hotter the ammo the sooner the failure. Muggsy has spoken.

When E.F. Muggsy speaks, people listen!

I'm okay if it turns out that I need to replace the follower after a few hundred rounds although the gun actually works fine with the broken follower.


Dave