Trouble with my new MK-9 Update on Last Page

[cee_Kamp]

New member here and new to Kahr, not new to defensive handguns.
My first time out this afternoon with my new Kahr MK-9. It was disappointing at best. I read all the stickies, did the initial clean and lube. Checked both of the magazines for correct spring installation position. I even checked the bullets were not touching the slide stop with the slide removed. The slide stop spring is correct, it's spring loaded in the down position. The trigger is awesome, the machining is wonderful, it's all stainless steel... But it doesn't run.
200 rounds of Winchester White Box 115 gr. FMJ for break in.
50 rounds of Remington Golden Saber 124 gr. std velocity next.
25 rounds of Remington Golden Saber 124 gr. +P after that.
Even with an "aggressive" thumbs away from the gun position, the slide stop self engages. So then I fired weak hand only (left) and surprise, same problem.
The slide stop self engaging problem happens with both magazines, and at no particular place in either magazine. It happened at round #2 and at just about any other point in either magazine. Every time I had the malfunction, I pressed the slide stop down and resumed firing. I don't believe I had the malfunction twice in any one magazine. Any suggestions before I call / email Kahr and send it back for repairs? Other than the slide stop self engaging problem, everything was good. If I can get it to run, it will be a great CCW choice.

[kerby9mm]

You checked everything that it could be & all I can think of is the recoil assembly. That was happening on a p238 I had so Sig sent me a new design spring and it never happened again. My mk9 is one of my favorite guns. Almost forgot I would call Kahr.

[jocko]

without my repeating it. look at the kahr tech section, under propper preppingof ur new kahr. there are soe thingsthere to check out and eliminate as possabilities. there is also a nice photo tutorial on the tech section showing the proper alignment of the slide stop spring to. under cw45 fixes. U need to checkthem out before sending it back. it could just be a minor thing.

It does sound to me like it is in the sldie stop spring, either being maybe to loose and maybe a slight snuggining of that spring can stop that. It that spring is a tad loose u will get what ur having. I doubt if rounds are hitting the insdie of the slide stop but easy tocheck out to. the prep guide explains all of that.

Other than the thumb thing which u have eliminated to, there is only 2 things left that can cause what is happening.

#1, slide stop spring.

#2 rounds hitting inside on thge slide stop lever.

[FLBri]

What Jocko Said ... +1
And I am voting slide stop spring. NOT locking back might be recoil related, but locking back when not intended would not be recoil system. As Jocko said ... only 2 mechanical possibilities.

Cee_Kamp ... I know it's frustrating, but stick with it, adjust the spring, and if necessary call Kahr and have them make it right. In the end, you will love this gun more than anything ... or you can sell it to me!

[wyntrout]

It's an all steel gun, not polymer... different slide lock spring setup.

Wynn

[zamboni]

I had the same problem with my MK9. I tried everything to figure out what was causing the slide to lock back but in the end it took a couple of trips back to kahr to fix the problem.

[kerby9mm]

You could try with slide locked no mag pull the slide back & see how fast & positively with a little click how the slide stop comes down. Could it be that the part of the spring that actuates the stop is a little short? I'm sure whatever it is will be fixed.

[wyntrout]

I just posted a pictorial thread on the K9 slide lock for member use:

http://kahrtalk.com/showthread.php?p=208564#post208564

A sample... the partially inserted slide lock pin showing the spring in the opposite side of the frame:



Wynn

[jocko]

not so wyn

It's an all steel gun, not polymer... different slide lock spring setup.

Wynn

same set up on the MK as the polymer..

[wyntrout]

OK... don't have an MK, but thought maybe they were similar... just tryin' to help.

Wynn

[jocko]

no problem., I just didn't want this fella looking for sumpin on his MK that was not there.If u could re picture ur photo of the slide stop spring and how it should lok, this willgive that fella a starting point...

[wyntrout]

This is a polymer frame's slide lock:



Wynn

[wyntrout]

Here's the Kahr take down video of the MK9:

http://www.kahr.com/Pistols/Kahr-MK9.asp

He addresses the slide lock beginning with 3:40 into the video:

http://www.youtube.com/watch?v=zXmSC...ailpage#t=220s

Wynn

[hal13]

New member here and new to Kahr, not new to defensive handguns.
My first time out this afternoon with my new Kahr MK-9. It was disappointing at best. I read all the stickies, did the initial clean and lube. Checked both of the magazines for correct spring installation position. I even checked the bullets were not touching the slide stop with the slide removed. The slide stop spring is correct, it's spring loaded in the down position. The trigger is awesome, the machining is wonderful, it's all stainless steel... But it doesn't run.
200 rounds of Winchester White Box 115 gr. FMJ for break in.
50 rounds of Remington Golden Saber 124 gr. std velocity next.
25 rounds of Remington Golden Saber 124 gr. +P after that.
Even with an "aggressive" thumbs away from the gun position, the slide stop self engages. So then I fired weak hand only (left) and surprise, same problem.
The slide stop self engaging problem happens with both magazines, and at no particular place in either magazine. It happened at round #2 and at just about any other point in either magazine. Every time I had the malfunction, I pressed the slide stop down and resumed firing. I don't believe I had the malfunction twice in any one magazine. Any suggestions before I call / email Kahr and send it back for repairs? Other than the slide stop self engaging problem, everything was good. If I can get it to run, it will be a great CCW choice.

I am having the exact same problem on a brand new MK40. The first time I went to the range, I shot 240 rounds, and had three failures, exactly as you described. On the 2nd or 3rd bullet, the slide would lock back, like the magazine was empty, but there was three or four bullets still in. I pressed the slide stop down, and the gun fired the rest of the magazine fired ok. The second time I went to the range I fired 100 rounds on MY MK40 and had two failures. I fired 100 rounds from my Glock 21, with no problems. I am using American Eagle factory ammo, so I doubt it is the Ammo. It was suggest that my thumb was hitting the slide stop so the next time I was at the range a fired another 100 rounds with two failures. I was very careful with my grip and am sure it was not my grip causing the problem.

It has been suggested that it might be the slide stop spring but I have visually inspected it and it looks ok. I called Kahr service and was very disappointed with who I talked to. They offered no help and suggested it was my problem. I need this gun to work 100% of the time, because I bought it for Self Defense, but cannot use it for that if I am not 100% confident in its performance.

I am very happy with the gun, even at the third time at the range, it is reasonably accurate. I was able to get 96% of my shots in the inner two circles. I need to get more exprience with it, becasue I am use to Glocks, as I can usually get 98% if my shots in the inner circle on an NRA D-1 target with my Glock. But I need it to work 100% of the time.

I would appreciate know if you figure out what is causing your problem, or you get a better response from Kahr than I did.

[wyntrout]

With the polymers, the spring can be bent or wind up UNDER the slide lock lever, instead on on top, and this will cause slide lock back with almost every shot. The free end of the spring to the right can get bent, too, when inserting the slide lock and pin.

Tightening the screw holding the washer, but not too tight, may help, too. My p40's screw needs tightening sometimes. If I start having slide lock-back problems, this is usually the case. Sometimes you just need a new SL spring. I keep spares for all of those parts on hand for each pistol... polymer, anyhow.

Wynn