light strikes FTF- odyssey of a kadet

[joerchi69]

Try a lighter hammer spring now. That should eliminate the slide closing on the last round.

Tryed today some lighter hammer springs. As before i used the ball pen spring in the FP channel and the shortened recoil spring (-6coils). With FP3. I changed from the original 20 lb hs to the 19 lb wolff spring. Shooting one handed 25 meters  CCI SV as it is my will to get it running reliable. I like the precision for the price. Because it leaves dirt i cleaned 3 times.
So in 50 rounds had 5 missing rounds in the chamber, one time the slide did not stayed open. One time the case was extracted only half way out of the chamber. I think the new 19 lb wolff spring is as more more powerfull than the original and used 20 lb mainspring. Dents row one.
So i inserted the 18 lb wolff spring. That went quite well. With 100 shots one missfire. Dents row two. The empty cases where thrown out more to the forward than to the side as used. Also with the 17 lb wolff spring i pluged in. On 100 shots 4 light strikes. One slide, one missing round and one stove pipe.Row three. Changing back to the 18 lb hs gave me 50 flawless working shots. Row 4.

19 lb
18 lb
17 lb
18 lb 

[joerchi69]

Picture of FP and spring...

That spring looks preferable because stronger / longer than to the ball pen spring i use in the moment. With that ball pen spring i suspect a occasional doubling of the FP hit on the brass, what i can guess looking to the pics magnificating the dents.

[painter]

When you install the FP is the spring preloaded? You could make a small spacer to fit on the small diameter of the spring pin. That would effectively lengthen the spring without adding spring weight. Those other springs you showed have much heavier wire. Shortening a spring does not make it weaker. Lengthening it doesn't make it stronger. It's about the wire diameter and the number of coils.

I don't think it's possible to double hit. I could be wrong.

I still think you could take a bit more off that pin Joe. Don't go as far as pin #2, but try to mimic the strikes in my pics.

[joerchi69]

Hello Painter,
yes the spring is preloaded. I had no problems so far within a radius of fishing for the spring outside of the slide.
If it ever happens i will give the spacer you mentioned a try. Or i will find fitting springs somewhere.
When looking to the second case in the fourth row on the last pic i posted, i assume a doubling. But can be something else. I just keep an eye on it when checking the dental imprints in future.

[DenStinett]

Haven't been keeping-up with your progress guys, but have you thought to contact Wolff directly and ask if they have a line on a;
Correct length but MUCH lighter Firing Pin Spring ?
I'd bet their Engineering Department could be a great source for you, given that; You've done / are doing a majority of the R&D ? And if they do come-up with the right Spring, they'd sell a ton of them !

Given (in this case), the only real need for the Firing Pin Spring, is to keep enough of the Pin back, to keep the Stop from falling out out of the Slide
Especially when you consider the number of Semi Autos out there that don't even use a Firing Pin Spring .... And that design; it helped win a World War !

[painter]

Next time I have mine apart I'll measure the details of my spring...wire diameter/length/od.

I bet there's thousands of them sitting in warehouses.

[joerchi69]

Quite reliable shooting with the kadet today. Compared to other days with this .22 lr.
A gunsmith examined and maybe reduced the headspace a very little bit. He told me that the cartridge rim now sets better against the barrel / chamber when delivered by the slide. Before there was maybe a little more play wich could lead to missfires when the FP hits the cartridge rim and the rim has no contact to the chamber/ barrel face. Gets just shoved against the barrel face with the light strike and fires with the second strike the primered rim having its barrel face anvil now. In theory.

18 lb hammer spring, ball pen FP spring, FP3, sometimes shortened sometimes original recoil spring i used today.
Only one light strike on 70 shots with the CCI select and 200 CCI sv with not one light strike.
I will try the lighter hammer springs next times. And the shortened original FP spring. Today was the first time the FP stop loosened with the ball pen spring in use. The FP stop moved out of its position and sticked over the slide. But did not completely left the slide.
3 stove pipes. Maybe one day i try a new ejector and do a lighter angle modifikation. https://czfirearms.us/index.php?topic=7863.0 The current one i filed extensive angles on wich helped a lot. But sometimes there is a stove pipe appearing..
Todays dents..



To reduce friction and fouling plus easy cleaning i use that Anschütz/ Fluna stuff. The gunsmith Jan Bruder
https://www.buechsenmachereibruder.de/ introduced it to me and my kadet.

https://shop.ahg-anschuetz.de/en/weapon-care-safety/cleaning/463/anschuetz-gun-ceramic-coating

https://ahg.anschuetz-sport.com/dateien/Downloads%20(eng)/Anschuetz-gun-products.Eng.pdf

I had to degrease and dry the complete gun first. I used break cleaner and Loctite 7063 degreaser, cloths and compressed air. Alfresco.
Then i sprayed Fluna on and wiped it down. Also in the barrel. And not to forget the kadets FP and its spring and channnel. Mags. Home from the range i now clean the barrel with Fluna, a nylon brush and patches.

[joerchi69]

On every 50 shots i had 3 slide not locking back on the empty mag issues. Reading this https://czfirearms.us/index.php?topic=22581.0 let me have a look to the slide stop and magazin follower interaction. Upper removed.
As recogniszed and shared by 75 plus the magazine spring was to weak to lift the slide stop spring. I pushed the slide stop spring retaining pin with a little punch to the inside of the frame to get the spring out. Holding it with pliers i flattened it just a little, feeling it bending i stopped. Back in, the mag follower now can move the slide stop easy. Looking forward for testing and forgetting that slide issue on the range next time.

toothpick pointing on slide stop spring retaining pin on a SP-01 Shadow frame

[joerchi69]

Used confetti from my desktop hole puncher to form a concept of how much headspace / rimspace is left with a round loaded in the chamber and the slide closed. The thought to it is, if the rimfire sits not tight against the chamber, the kadets firing pin can shove the cartidge forwards and looses its momentum to ignite the primer on the first strike.
Used a calliper to measure the confetti thickness and height of the empty headspace. And the brass rim height. And a feeler gauge to measure the crack between slide and upper in the area where the recoil spring housing is.
For example with one confetti between brass and breechface the slide just touches the upper chamber area metal to metal. With two confetti not. With a drop of oil the confetti stays on the breechface. Removed the extractor claw for better handling. I do not post numeric values with intend. Just like to show the "method" with some pics.

confetti placed


confetti and round placed


toothpic(k), pointing to contact area with improvised feeler gauge





To reduce the stress on the barrel pin,
https://czfirearms.us/index.php?topic=39826.msg823843#msg823843
pre headspace/rimspace reducing i could add the two of these improvised spacer rings. To have the same time contact at both points when the slide closes. The slide and slide housing where these spacers are and the lock up point from slide at the breech face to the barrel face.
 Now with the reduced space for the cartridge rim i only can use one spacer to have the contact in the same time.



Barrel pin  3x12mm, quick and permanent fix
https://czfirearms.us/index.php?topic=51323.msg313472#msg313472

[joerchi69]

Todays dents FP 3, FP ball pen spring
row 1, 18 lb hs    (original recoil spring)
row 2, 17 lb hs    (original recoil spring)
row 3, 17 lb hs    (shortened recoil spring)



Best thing first - no light strike on 300 CCI sv.
First box of 50 rds i had no slide not staying open on the last round issues. But 3 times a missing round not striped from the mag into the chamber.
Second box 2 slide issues. After that first 100 shots i switched from the 18 lb hs to the 17 lb hammerspring - which gave me light strikes the first time i used it some weeks ago. No light strikes but 3 slide issues on pack three. Box 4 one slide, box 5 i additonal switched to the shortened recoil spring. To give the slide a little more power to go further back. No slide issues for that fifth box. One on the sixth pack.

 I had hoped that slide not locking back on the last round to be solved with the tension reduction of the slide catch release spring, to help the folower of the kadet mag to push the lever up. Then i took a closer look inside with removed upper.
Bingo. The follwer is touched and slowed down by the slide catch to early on a wrong spot.



Same thing with the second mag. It looked already filed on that spot. So just enough metal had to vanish to give untroubled way to the red plastic. Hope it proves right next time on the range. 


Cleaning the upper i found stress marks again.



The backwards moving slide gets pressed up when cocking the hammer and rubs against the upper.
The firing pin retaining plate i already had shortened last year to get it on a equal hight to the slide - also when pressed up by the hammer.
It is easy to see, holding the assembled pistol against light, if there is a contact area. The files where still on the table..





Puzzled we found last year a club members Kadet´s FP retaining plate shatterd to pieces - but still in place and working.



 Belike it repeatedly hit the upper on its way back because it was sticking up the slide.

[joerchi69]

The conversion kit is truly a conversion kit.
Converts me into a wannabe gunsmith.
 

Like it !

[joerchi69]

From https://www.rimfirecentral.com/forums/showthread.php?t=546664#/topics/546664?page=1

...case rim will be pinned flush against the barrel face, and hit hard enough to detonate the primer.

If you get poor ignition because of excess headspace it's better to fix the headspace on the rifle rather than measure hundreds of cartridge cases.

[joerchi69]

How to calculate a matching front sight and how to adjust an iron sight

I hold my sights under the targets black into the white paper area for the contrast. And, real cause, it was explained to me like that. Meanwhile my convercion kit`s rear sight is completely screwed in direction to up. And the point of impact could still be higher. The white stripe between front sight and target black could be more obvious too, for visual hamonics as wide as the light passing by the front sight vertically. I searched for informations on iron sight adjustment. And if i would need a longer - or shorter front sight to correct the POI. And to get the rear sights centered additionally.

I liked that explanation:   https://en.wikiversity.org/wiki/How_to_adjust_an_iron_sight

If your shot is below (needs to be higher) your target using both sights facing directly at your target, the rear sight should be moved higher or your front sight should be moved lower.

 Always remember: Move the rear sight in the same direction you want your point of impact to move & your front sight the opposite direction you want POI to move.


My special-needs teacher here
https://stores.kensight.com/front-sight-height-guide/
got me to understand that i can calculate the height difference for a matching new front sight with the shown formula.

So in my case i will go down with the front sight - install i shorter one. To calculate the new front post height i would have to center my rear sights, go shooting holding my point of aim with the sights, and measuring how much i shoot low. Put it in the formula..  Thats how i understand the theory. To be proofed..


 

[joerchi69]

Next time I have mine apart I'll measure the details of my spring...wire diameter/length/od.

I bet there's thousands of them sitting in warehouses.

That is a very kind offer. I looking forward for details. Sure get it within a radius of a nice motorcycle ride. Here at the Black Forrest area out of a cuckoo clock or from another major branch of industrie.

https://vimeo.com/152027144

slightly modified cuckoocadet

[joerchi69]

Today i tested the 16lb hammer spring and FP3 with other components. Again with the CCI sv. The 17lb had avoided light strikes completely, with a ball pen spring for the FP and the cut down recoil spring. And in vain i hoped the slide issue was fixed with loosening the slide catch release spring and clearing the mag folower from rubbing on the slide catch bevore getting lifted after the last round.  I started the 16lb main spring in combination with a shortened kadet firing pin spring and the shortened recoil spring. 9,3cm left from the uncut original length wich i have in 10cm and 10,3cm. Two times in beteen the 650 shots i cleaned the locking areas, slide to barrel.
First box of 50 with 3 light strikes and 2 rounds not striped from the mag. 1 slide issue. Row 1.
Second box 2 light strikes. So i wondered if the reason is the weaker 16lb hs, the stronger cut FP spring compared to the light ball pen spring or if the shortened recoil spring is may be not closing the slide complete. So i tested some combinations.
Third and fourth package ran just fine with the ball pen spring on the FP. Row 3.
Box five i put in the orig. length FP spring - explicitly 14 missfires. Row 4.
Box six i put in 2 ball pen springs in a row in the FP channel. 1 light strike 1 slide. Box 7 one light strike one stove pipe . Row 5
Box 8 i changed to the orig. length recoil spring to get on light strike and one slide issue. Still two ball pen springs with Box 9 no light strike but one slide. Row 6.
Box 10 back to one ball pen fp spring. Still the orig. rec. spring. One light strike, 2 stove, 3 slide. Box 11 back to the minus 6 windings shortened rec. spring. No light strikes, no slide. One case gets ejected poorly, scraping out of the side.
And i realise that the first round chambering from the mag is doggerel.
So box 12 i install a fresh recoil spring just cut down minus two windings. Gives 4 slide issues and one rd is not chambered. Round one chambering feels slick.
So box 13 i cut it down on minus 4 windings still earning 3 slide issues.

Will go back to the 17lb hammer spring. Playing with cuting down the recoil spring and try an all original FP will come next time. Some more FP modifying maybe. The importance of the lightness of the FP spring astonishes me. Good result.
The feeling with the orig. length rec. spring is better but the cut down exemplar to in the moment 9,3cm, worked much better. Funambulation. 

todays dents


rows from the side, cases and missfires


personal record 650 - thanks to Den`s UpLula mod ! more trigger time


some hits getting centered, hope repeatable

25m two handed, shooting glas on dominant eye