What causes the cracks in the mags?

[Tilos]

CJB:
To your point and as I mentioned before, a minor scratch on the tooling that's used to bend/form the shape could transfer to many, many mags in a high speed manufacturing process.

Once a large amount of mags are accepted from a vendor, and later found to have some defects in use, the only choice would be to have a recall or deal with it on an individual bases by replacement.

It seems Kahr has decided to replace any that prove defective in use.

I'll ask anyone who have delt with this issue, has Kahr asked for the GUN to be returned or just the mag??

Again, a stress point could be so small as being undetected with the naked eye.

Orphanedcowboy: Thanks for posting.

Tilos

[muggsy]

Originally Posted by Tilos

The mags become "work hardened" from the bending/forming process and crack in the corner, where the metal is stretched/coined the most.
They could be annealed and re-hardened for uniformity but this would add cost to the process.

I've never seen a cracked mag but ask those who have, was there any score marks on the inside of the corners that cracked.

Any tool marks inside could create a stress point for a crack to start.
I can tell from the finish that the mags are tumbled/shot peened on the outside to smooth the surface but have not looked inside of one too closely.

just guessin'
Tilos

Tilos, as a machinist I agree with your analysis completely.

[michpatriot]

We really need pics.

[Orphanedcowboy]

Originally Posted by Tilos

It seems Kahr has decided to replace any that prove defective in use.

I'll ask anyone who have dealt with this issue, has Kahr asked for the GUN to be returned or just the mag??

Tilos

They only asked for the magazines back, even shipped two prior to receiving them as well.

Originally Posted by michpatriot

We really need pics.

That was an afterthought once they were already in the mail, sorry.

[CJB]

Originally Posted by jocko

I did not know that......
..... kahr has ask for some of the guns to be returned with the split magazines. That to me was some sore of indicator that it could be gun related. I think it was wyn who had alot of split magazines and correct me if I am wrong but I think it took an entire new gun to get him right.

I'm not sayin' that it can't be the gun, I'm just sayin' that cracked magazines are nothing new under the sun. Could also be that Kahr wanted to rule out the gun, or... they knew something they're not saying, or both.

Its ok Jocko... I think we're really on the same page... I'm just giving some horizontal leeway to the whole discussion

[CJB]

more thoughts....after more reading here....

Tooling, work hardening, variable metallurgy, or pistol variables.

E. All of the above.

I've done my share of manufacturing oversight. Its a wild ride to keep things right. No matter how simple you make it, somebody is gonna find a way to screw it up.

[Orphanedcowboy]

Well the replacement mag arrived today. It is slightly different than the originals.

[jocko]

in what way??> a photo would be very nice..

[jocko]

Originally Posted by Tilos

CJB:
To your point and as I mentioned before, a minor scratch on the tooling that's used to bend/form the shape could transfer to many, many mags in a high speed manufacturing process.

Once a large amount of mags are accepted from a vendor, and later found to have some defects in use, the only choice would be to have a recall or deal with it on an individual bases by replacement.

It seems Kahr has decided to replace any that prove defective in use.

I'll ask anyone who have delt with this issue, has Kahr asked for the GUN to be returned or just the mag??

Again, a stress point could be so small as being undetected with the naked eye.

Orphanedcowboy: Thanks for posting.

Tilos

magazaines, they are not gonna recall them, evenif they know some are bad, as "wheredo they start". They will replace bad magazines as long as they are sent back, I have no doubt about that. They itis not abuse but a defect of some some sort. I don't know who makes kahrs mags but they are stainless, they don't seem cheap in qality but yet something is causing this splitting and it is neve rin the welds. Companies that makes magazines normaly know how to make good magazines, that is their job, we have seen badmagazinesfor at least over 2 years, so I just ain't buying "poor" steel or bad batch. Just assiming here maybe more than I should to, but I still tend to think it is more gun related and I can't prove that at all..

[Orphanedcowboy]

Pictures:









Changes I noticed:

They moved the engraving up the side

The cut at the rear is larger

The radius on the back corners is bigger(not as tight where it is formed and also cracks)

The round count windows are actually lined up now

The edges of the lips are smoother, more polished feeling

The magazine it self feels grainy, like it could use a little longer in the tumbler

I also noticed the first round, last round loaded, the rim sets in the groove under the rim of the second round on both mags and no matter how hard I tried I cannot get it to seat flush with the back of the mag. This pistol has been flawless with every round fired though so it doesn't seem to bother the pistol as much a it bothers me.......