P-40
Chaim,
The P-40 had some initial challenges, it is true, because it absolutely pushed the design envelope for a lightweight, small, full-power pistol. It was supposedly just a slightly enlarged P-11, which had faced similar challenges, but that wasn't enough.
The magazines had to be changed to feed the larger bullet higher up the ramp. KT made the change and replaced older mags for free.
The feed ramp also needed to be shortened and I believe the angle changed slightly. KT did, and made good on any old barrels. Other than these two upgrades, I am not aware of any mechanical problems that the P-40 had that would not occur in any similar pistol, including the P-11, from time to time.
I consider wear and tear on certain parts, like extractors, ejectors and slide stops, to be normal wear. In the case of KT, the slide stop and ejector are stamped parts, so I expect them to wear out. They are inexpensive and very easy to replace. When mine have broken, the gun continues to function. I keep them on hand and change them every once in a while if they have not broken (ca. 1500 rounds). Both models take hi-cap S&W mags, a nice plus for home defense or as a backup.
The biggest problem with the P-40, and the real reason KT discontinued manufacturing it, was because they had a large number of returned guns that had no problems. The shooters could not handle the recoil and would limpwrist the guns, causing feeding and ejection failures. Improper slide lubrication could have also contribute to this. As with any semi-auto, a light film of grease is necessary to get consistent slide functioning and to protect the parts from wear. You cannot shoot a KT dry, and it will sling oil off the fast moving surfaces in a short time.
I carry one of my three P-40's every day. They are absolutely reliable, but they need maintenance, as with any carry gun. However, because the gun is so light and small, the balance of the feeding/firing/ejection sequence must be maintained. A lot of crud from not cleaning the gun, improper lubrication, weak recoil springs, weak grip, etc., could all cause functioning (read "slide travel") problems more quickly in the KT's than in heavier guns that have more mass to be more forgiving.
Understanding all this, the KT P-40 has the best combination of concealed carry characteristics for me, and money is not a consideration when I am out to protect lives.
My two P-11's also run consistently. I just shot an extensive IDPA match yesterday (ca. 130 rounds) with my oldest one (serial # < 3000, about 3,000 rounds through it). The gun performed flawlessly and accurately, considering it is meant for use at under 20 feet for self defense and not as a target weapon. Most of the stages required shots at 20+ feet, and a lot of head shots. Those are very challenging for any small gun, but I did fine with the little guy, even compared to the full size 1911's. I'm just not quite as fast on the trigger or aiming. I beat out a Glock 26'er on almost all stages, and numerous 1911 pattern guns, almost all of which had function failures (Kimbers & Para's). One Glockster in our group had a light strike and performed a TRB. I would have just pulled the trigger a second time and the gun would have gone bang. (Then TRB if necessary).
There are those who have had bad experiences with KT's. Early manufactured guns had some challenges (trigger pull too heavy) that the factory has been excellent to take care of. The more recent guns rarely have a problem of any kind. They are now a mature product for a specific use--concealed carry or a small but powerful kit gun. The triggers are their safety, just like on a revolver. I consider my KTs to be my thin, lightweight 11-shot revolvers that reload very fast. Most problems relate to improper lubrication and limpwristing.
The design is also very simple and easy to understand, making maintenance and even personally performed upgrades and modifications possible. I have done a lot to my guns to get them to be exactly what I want, since I stake my life on them. That could be another thread.
Obviously, I could go on. I'll stop here by saying again, the KT is the best combination of concealed carry characteristics in a 9MM/.40 S&W pistol out there, if you can handle them. There is even a .357 SIG conversion barrel available for the P-40 for those who think that caliber is the ne plus ultra of anti-personnel rounds this week.
http://www.ktog.org/vbulletin/
http://www.kel-tec.com/
CB3
sideways, weak handed, two finger...won't fail. 