K9 with extras

[Wonmug]

Bought a K9 back in 1998 -- still have it. When I first fired it, I had 1 out of 3 failures to return to battery;I returned the pistol to Kahr, They polished the ejector a bit and did some other tweaks. After that she behaved well. I took to firing mostly +p and 1240fps 124gr mil loads. A tech at Kahr suggested that I might want to try the K40 recoil spring. This, to improve on return to battery and to take some of the "snap" out of the felt recoil. That works like a charm! As I remember it, the K40 spring has 23 wraps (turns) while the K9 one has 21 wraps. -- Can be ordered from Kahr. I added the crimson trace laser grips --- they're still working fine. Also bought the stainless guide rod etc. Then I bought the ported barrel --- big mistake in my opinion. The ports are slots cut into the top of the protruding barrel end. The problem is that they were slanted, bottom end toward the breech, top toward the muzzle. The result was that many of the rounds fired had metal shaved off by those sharp slot edges as they exited the barrel -- bad. Then came the Kahr T9. Its barrel is basically the extended ported K9 barrel but without the ports! It is basically a drop-in for the K9! A tad of polishing may be required to get a smooth fit. I like the half-inch extended barrel for the improved accuracy and velocity, without the added size & weight of the T9. This is my go-to service 9.

[ripley16]

You're saying a T9 barrel fits into a K9 slide and operates just fine? I always thought there we differences between the two.

[Canine Dave]

Bought a K9 back in 1998 -- still have it. When I first fired it, I had 1 out of 3 failures to return to battery;I returned the pistol to Kahr, They polished the ejector a bit and did some other tweaks. After that she behaved well. I took to firing mostly +p and 1240fps 124gr mil loads. A tech at Kahr suggested that I might want to try the K40 recoil spring. This, to improve on return to battery and to take some of the "snap" out of the felt recoil. That works like a charm! As I remember it, the K40 spring has 23 wraps (turns) while the K9 one has 21 wraps. -- Can be ordered from Kahr. I added the crimson trace laser grips --- they're still working fine. Also bought the stainless guide rod etc. Then I bought the ported barrel --- big mistake in my opinion. The ports are slots cut into the top of the protruding barrel end. The problem is that they were slanted, bottom end toward the breech, top toward the muzzle. The result was that many of the rounds fired had metal shaved off by those sharp slot edges as they exited the barrel -- bad. Then came the Kahr T9. Its barrel is basically the extended ported K9 barrel but without the ports! It is basically a drop-in for the K9! A tad of polishing may be required to get a smooth fit. I like the half-inch extended barrel for the improved accuracy and velocity, without the added size & weight of the T9. This is my go-to service 9.

Polished the ejector? I'll have to remember that trick. Unique pistol, unique maladies.

[Wonmug]

Absolutely a perfect fit. As I said, a bit of polishing on the sides of the breech block were needed to make everything smooth.
Cheers.

[Wonmug]

Don't forget to polish the feed ramp on the barrel also...
Cheers,

[Canine Dave]

That guy knows of what he speaks. I even had to polish my striker spacer. Had a little booger on it.

[thinman]

Hello Wonmug -- Your post about putting the 4" T9 barrel in your K9 is very interesting. I have found the effects of a longer barrel on velocity can be quite significant in 9mm pistols. Have a 4.5" barrel Canik TP9SF that I have compared with a 3" barrel Kahr PM9 . Using handload 124gr bullets the Canik showed 1,092fps and the Kahr showed 1,001fps on my chronograph. Comparing the power factors ((bullet weight x velocity) / 1,000), Canik power factor = 135.4 and Kahr power factor = 124.1. The 135.4 power factor is about what I have found for more than one factory ammunition power factor. USPSA competition ammo in 9mm is required to be at least 125 power factor, and I can say from experience that steel plates fall a lot better with 130+ power factor ammunition.
Do you have any saved data you would share about how much velocity difference you found between the 3.5" barrel K9 and the 4.0" barrel K9?
The half inch longer barrel doesn't change the pistol's carry profile very much but the velocity improvement would be nice.
Also, whose stainless guide rod did you use?
Thank you.

[SUOMI69]

Wow! You teach math? Crazy technical but fun.