I have put about 1,000 rounds through my 22 Kadet kit so I thought I would share. The 22 Kadet conversion kit replaces the 9mm slide, recoil spring/guide, and barrel with a slide housing (containing the 22 cal barrel), a seperate slide piece (that cycles), a small recoil spring/guide, and 22LR magazines. The design is non-locking blowback with the slide housing/barrel "fixed" to the frame. Therefore the slide housing/barrel must be tightly fit to the frame. There are contact points on the kit that can be filed to fit the frame with a tight friction fit.
Be warned that the Kadet fitting instructions are slightly wrong for the P01. They say to fit contact "A" (the left front lower barrel lug area) and then fit contact areas "B" (short rail segments on the slide housing). Since the P01 has a short "dust cover" section of the front of the frame, the "B" contacts will be the first point of resistance, not the "A" contact. If you follow the Kadet kit instructions, you could end up removing too much from the "A" contact. Fit the "B" contacts first, then the "A" contact, if need be.
The stock P01 slide stop inner portion is too short to contact the 22 cal magazine follower, so the slide will not lock back after the last 22 round is fired. The solution is to email CZUSA and get a free PCR slide stop. The PCR slide stop has a longer inner portion that will reach the 22 magazine follower. Please note: the PCR slide stop should only be used when shooting 22LR, not when shooting 9 mm. On my pistol, the slide stop spring (in the frame) was pushing a little too hard on top of the PCR slide stop. The 22 magazine spring was not quite forceful enough to counter the slide stop spring. I did not want to alter the slide stop spring and change anything with the 9 mm action. So instead, I filed a small amount of metal from the rear of thin groove on top the PCR slide stop shaft, where the slide stop spring seats on the slide stop. This slightly decreased the downward pressure the spring has on the PCR slide stop and allows the magazine spring to lock the slide when empty.
The stock P01 single action trigger was stagey and gritty. Also the hammer would cam back in single action, enough that I could see it while slow aiming and overanticipate the shot. I solved both with my sear action job (see my other topic regarding this).
I did not need to perform any reliability tuning as I have had zero malfunctions with 1,000 rounds. I recommend starting with CCI 40 grain MiniMag (high velocity) 22LR ammo. Because the P01 has a compact frame, the 22LR conversion magazines protrude from the bottom of the magazine well.
The only extra maintenance issue might be 22 goo in the firing pin hole. After 1,000 rounds, you may want to clean the firing pin and firing pin tunnel. There is no firing pin saftey block and the firing pin can be removed easily via a firing pin stop at the back of the slide. Be careful though, the firing pin is spring loaded! Also note that the firing pin must be correctly rotated to key into the firing pin stop hole during reassembly.
I highly recommend the Kadet Kit to all P01 owners as an inexpensive training pistol. It is 100% reliable and fairly accurate. It is a good way to learn trigger control and it saves a ton of cash on ammo. My Kimber 1911 22LR conversion kit on a Colt Combat Commander frame is a more accurate tack driver, but that pistol has a fine tuned 1911 trigger action.
