Recoil Springs, Check your MK9 or MK40 [Archive] - Glock Talk

PDA

View Full Version : Recoil Springs, Check your MK9 or MK40


BillHickock
08-21-2007, 10:48
First, this is not a KAHR bashing post. This is how to make an awesome gun even more awesome and reliable. In my case its the MK9, but may also apply to the MK40.

The first week I had my MK9, I shot about 100 rounds through it with flawless operation. I took it back home from the range and removed the slide to give it a very close going over visually and a good cleaning. I wanted to see if there were any problems (if any)I needed to catch right off. Well I found one...a very minor one. The slide appeared to be peaning the slide stop on my stainless steel frame. It was slight, but enough to cause a sharp edge to form on the frame stop. This may be just a part of Kahrs "200 round break in period" we hear so much about and no big deal. I also noticed a slight warpage of the recoil spring guide (plastic), when the slide was retracted and the spring was under tension. Long story short here is what stopped the peaning.

1. Wolff sells 3 different springs for the MK9. These are non captive springs and the springs have different tensions.
A. 20lb (OEM or Stock replacement).
B. 22.5lb (Extra Power).
C. 24.5lb. (Maximum Power)

I opted to buy "B" with a steel guide rod as a test, but I know all three are available in a calibration pack for a little more money. I lucked out and got the right spring, the 22.5lb.

Here is the Wolf websight:http://www.gunsprings.com/SemiAuto/KahrNF.html#MK940

Even though I bought the Wolff steel guide rod and it worked great, I purchased a stainless steel guide rod from Kahr @$40. (a little expensive, but cosmetically nice with the SS MK9). It replaced the Wolff rod and made the springs captive once again using the stronger springs. There has been absolutely no peaning and the slide operates much more smoothly. I also took the dremel and using a fine metal polishing wheel, removed the sharp edges from the stop on the frame. That was about 200 rounds ago and no more sharp edges, burrs or peaning. If I were going to shoot the +P or the ++P ammo, I would consider the recoil spring upgrade if peaning or sharp edges turn up on the frame slide stop. Gunsmiths please chime in. I think anyone with a little mechanical ability can do this with no problem.

Thanks!
Bill

outerlimit
08-23-2007, 00:17
I haven't seen anything like that on my frame, but I do know the plastic guide rod is junk and I had the same problem. Plus the stock spring seems kind of weak. I know alot of other people have also had problems with the plastic guide rod bending or warping after a small amount of firing, like 100rds or so. Same thing with me.

I got the Wolff stock (#A. mentioned in your post) replacement a couple of years ago, couldn't be more happy, except the finish on the Wolff part could be a little more durable, but not a big deal.

The "stock" weight replacement from Wolff seems heavier than the stock recoil spring that came with the Kahr MK9. I'm very happy with it.

BillHickock
08-24-2007, 09:41
Good to hear your spring has held up for a couple of years. I probably could have went with the "A" spring as well, but I wanted to make sure I stopped the peaning in its tracts. To bad Wolff chose not to make a Stainless guide rod. I would have went with theirs because of the non-captive design.

Take care and good shooting!

Bill

NailShooter
08-28-2007, 02:44
outerlimit
Senior Member


I haven't seen anything like that on my frame, but I do know the plastic guide rod is junk and I had the same problem. Plus the stock spring seems kind of weak. I know alot of other people have also had problems with the plastic guide rod bending or warping after a small amount of firing, like 100rds or so. Same thing with me.



+1

The stock recoil spring assembly is GARBAGE. Mine bowed shortly after I bought the gun. I put the Kahr s.s. rod in mine also.


Nail

norfdet893
09-03-2007, 07:37
I was shooting an IDPA "compact" match with my PM9 when the recoil spring collapsed. I started getting FTE's. I called Kahr and they sent me a new assembly and once replaced, everything was fine.

BillHickock
09-06-2007, 09:45
Originally posted by norfdet893
I was shooting an IDPA "compact" match with my PM9 when the recoil spring collapsed. I started getting FTE's. I called Kahr and they sent me a new assembly and once replaced, everything was fine.


I'm really surprised that Kahr does not provide a quality recoil spring and guide from the factory. Its a weak link in a great gun and its costing them. Unlike me, not everyone likes to be a rookie gunsmith and try to find out what makes it tick.