My Kadet experiment

[DenStinett]

A lot of great work here Paint

Never cared much for .22 Rounds with waxed Bullets
They cause a lot of loading /extraction issues, even in Revolvers and Bolt Guns
Back in the day, when there wasn't much else available, I'd actually take the time to wipe the wax off of each and every Round before a Match / Range Session

[painter]

Thanks Den.

During the ammo shortage CCI SV became ridiculously over lubed. So much so that the wax would deform on the bullet tips where they rubbed on the paper boxes. Some would even have chunks break off. The thing about the CCI was it was typically available, and remained reliable with stock springs.

I don't subscribe to removing all the wax lube though. I'd be afraid of leading issues.

[handgun2]

great thread, and ideas.. I am a guy w/ the 13lb spring and altered retaining plate in a PO6 gun frame that ran flawlessly until dropped down to a 13lb and 11lb main spring.. started tinkering..  haven't shot the kadet on that frame yet again.. as it needs a new sear cage springy... thingy..   CGW working to fix w/ me.. ahhhh,    but NOW, I feel rejuvenated to start tinkering again based on this information!

thank you all,

K in MI

[painter]

great thread, and ideas.. I am a guy w/ the 13lb spring and altered retaining plate in a PO6 gun frame that ran flawlessly until dropped down to a 13lb and 11lb main spring.. started tinkering..  haven't shot the kadet on that frame yet again.. as it needs a new sear cage springy... thingy..   CGW working to fix w/ me.. ahhhh,    but NOW, I feel rejuvenated to start tinkering again based on this information!

thank you all,

K in MI

I remember your work well K. I wish I had a lathe and a mill to do some more firing pin experiments.

Based on the strike depth I don't think a much weaker spring would work. It might if you could increase the footprint area without adding to the resistance of extra brass being crushed.

I also believe there are other tolerances in the Kadet that pile up and contribute to the requirement for a strong spring.

It's fun stuff.

[handgun2]

Painter,

you have me ' ready' again to dive into the Kadet / light spring areana again. thanks.  didn't think anyone cared anymore.  So, wondering, have you ever 'measured' the depth difference's in firing pin hits? 

thanks,  would be a boon if you did and can publish.  I kept trying to keep penetration to same depth.. NEVER really thought about 'where' the strike should be? could be? better?

please advise,
thanks
K in MI

[Peacetilence]

FWIIW, I got inspired by this thread to try some stuff, here are the first results. Setup:

 - CZ Kadet II Adapter, brand new (got it last Mon ) w/ modified firing pin, see pictures below. This is the only modification to the pin I have done so far.

 - CZ 75B frame (2nd run Cold War Commemorative) w/ CGW 15# hammer spring and CGW short reset lifter. Everything else is original (well, G10 grips... ) (Edit: oops, forgot the CGW trigger pin and trigger return spring...)

I ran various ammo through it (% fired on 1st strike):

 - 100x CCI Mini-Mag 40gr RN (90%)
 - 10x CCI Velocitor 40gr HP (90%)
 - 10x CCI Stinger 32gr HP (100%)
 - 50x Aguila HV 40gr RN (80%)
 - 50x Aguila SV 40gr RN (80%)
 - 60x Fed Target HV 40gr RN (90%)
 - 20x Fed American Eagle HV 40gr (100%)
 - 20x Remington 22 Thunderbolt 40gr RN (85%)
 - 20x Winchester M22 40gr RN (85%)

All misfires would go off on second strike via DA. I had two rounds that did not fire after a 3rd strike (1 Stinger and 1 Fed Target) but went of after reloading turned 180 deg (top right casing in the picture w/ the 3x3 F casings is one.)

Overall I would guess the reliability is about 85%. I wasn't too bothered by this since I only use the gun for informal shooting -- it actually helps me practicing DA pull and flinch avoidance

Possible improvements:

 - I ground the corner of at a 45deg angle. A steeper angle would reduce friction on  the rim side of the case further (you can see the ledge impression on some impacts)
 - if this were be a remanufactured pin, I would have the impact surface angled, ie. leave the outer edge where it is and extend the inner edge by 1/100" into the chamber, resulting in a slightly sloped impact area. This should be safe for dry fire, but allow for better energy transfer into the rim.
 - relieve the surface where the pin rests on the stop plate by 1/100" to 2/100" to give the hammer slightly more time to transfer energy.

I would like to try the last point, but I don't have the tools to do this. I do know a machine shop in this area, I'll try to talk them into it

[painter]

Painter,

you have me ' ready' again to dive into the Kadet / light spring areana again. thanks.  didn't think anyone cared anymore.  So, wondering, have you ever 'measured' the depth difference's in firing pin hits? 

thanks,  would be a boon if you did and can publish.  I kept trying to keep penetration to same depth.. NEVER really thought about 'where' the strike should be? could be? better?

please advise,
thanks
K in MI

Sorry, I missed this post.

I probably have some cases around from a stock firing pin and spring. I'll have to look, but to answer your question...no I never measured depth. I don't have a stock pin anymore so I can't reproduce any data on stock pin and strike depths with various springs.

I did shoot again tonight. I put 105 rounds downrange and had 1 light hit between rounds 50 and 55. It was a Geco round, and did go off on the second strike. That would be around round # 440. That would have surpassed my goal of 400 round, 100% reliability. I had no further light hits for the next 35 rounds.

I'm calling this a success. I'm going to clean the kit, and start counting over without any waxy buildup on the feed ramp to verify that I can go 400 continuous rounds with 100% reliability.

 K has me thinking about strike depth influence, so I may at some point get a new pin and do some further testing to see if I can determine if it's depth, footprint, or a combination of the two that determine reliability. I could put a stronger spring in and get some depths with the modified pin, but I'm not sure what that would prove.

Stay tuned.

[Boris_LA]

Inspired  by ideas on this thread i have modified two firing pins on my Kadet slides. Tested them last week on two different frames. SP-01 with 13lb main spring and SAO with 15,16,18lb springs. The results last week were: 13lb spring 70-80%, 15lb spring 80%, 16lb 90% and 18lb 100%.
Yesterday i have replaced both firing pin springs with softer ones stolen from the ballpens. Tested today again with 100% reliability on both frames including 13lb spring. Only tested with two ammo brands CCI SV and SK Standard plus. Not a single misfire today. Great! Now my SAO gets a lighter main spring as well. Before i was forced to use 18lb to use it with Kadet kits. 

[painter]

My next test will not include CCI.

[rhart]

Nice trick - using a spring from a ball point pin. I baked my spring in the oven to temper it down and make it weaker.

[painter]

As I posted earlier, I'm using the spring that came with the CGW extended pin.

[Peacetilence]

Quick update:

Possible improvements:

[..]
 - relieve the surface where the pin rests on the stop plate by 1/100" to 2/100" to give the hammer slightly more time to transfer energy.

I would like to try the last point, but I don't have the tools to do this. I do know a machine shop in this area, I'll try to talk them into it

I had that done last week (10/1000"). Tried the mod yesterday, ran about 200 Fed. AutoMatch at 95% reliability w/ the 15# main spring.

The next step will be a lighter FP spring, I have one coming and will report back w/ the results.

[DenStinett]

I took the KADET, mounted on my B-SA Lower (with the stock Hammer Spring) yesterday
Ran 50 Rounds of Federal Bulk with 100%  reliability   
Then I ran 50 Rounds of Troy Landry, CCI .22lr Mini Mags
They were about 15 - 20% reliable (always fired on the DA second try)     
Have yet to have an issue, with the Federals, so I can't figure-out way the issue with the CCIs   

[Boris_LA]

I took the KADET, mounted on my B-SA Lower (with the stock Hammer Spring) yesterday
Ran 50 Rounds of Federal Bulk with 100%  reliability   
Then I ran 50 Rounds of Troy Landry, CCI .22lr Mini Mags
They were about 15 - 20% reliable (always fired on the DA second try)     
Have yet to have an issue, with the Federals, so I can't figure-out way the issue with the CCIs   

Mini Mags have hard wax (paraffin?) coating. Do they chamber all the way? Clean chamber? Lite recoil spring? Just thinking out-loud.

[DenStinett]

Mini Mags have hard wax (paraffin?) coating. Do they chamber all the way? Clean chamber? Lite recoil spring? Just thinking out-loud.

Hey Boris:
These MiniMags are Copper Platted, not waxy Exposed Lead
https://www.midwayusa.com/product/234289/cci-mini-mag-high-velocity-ammunition-22-long-rifle-troy-landry-special-edition-36-grain-plated-lead-hollow-point-box-of-300
They seem to chamber cleanly
All Springs are stock
As stated, I have yet to have a single issue with the cheap Federals or other Copper Plated / Washed Rounds
I will not run Waxed / Lead Rounds through my Autoloaders