The Original CZ Forum
CZ PISTOL CLUBS => CZF KADET KLUB => Topic started by: redlightrich on November 19, 2017, 07:58:00 AM
-
Hello all, I have 3 kits, for 3 guns. On my newest frame ( 75B SS) When I have my Kadet mounted, the gun will not feed the first round. This is when I use new or broken in mags, loaded to 10 rounds. I have tried racking the slide or dropping the slide from the release. The round gets stuck in the area just above the feed ramp, and just below the chamber. Yes, there is a lip there, 90 degrees, about .060 wide. I am afraid to round it, as it makes up part of the chamber wall, although that may cure this.
The same issue occurs, almost regardless of ammo type, I say almost, as Rem GB36g hollows, feed fine, but are a hair shorter OAL than most other ammo. And the Rem ammo cruds up the gun in a hurry, so it is a poor fix. I also would like to hit what I aim at.
Round nose makes no difference, plated makes no difference. Greasy ammo ( Norma, doesn't help)
These same kits that fail to chamber on my 75B, work fine on my SP-01.
I measured the difference in frames, and all critical dimensions are within .0015. I did not measure mag catch to frame rail, as it would be tough to get a good accurate measurement there.
I have tried to hold the mag as high as possible ( using pressure from a bench) while I rack the slide, and no luck. I need 3 hands to try the mag lower, as when I try that, it falls out of the frame. Maybe some tape around the mag to provide friction as a test?
It takes me 2 or 3 racks of the slide to chamber the first round. The rest of the mag runs fine.
If I load the mags to 5 rounds they feed fine. If I go to 7 they fail. I did not yet try 6, but I would like it to be right. If I load to 10 rounds, but carefully tip up the top round, I can get it to feed most of the time, but not always.
This same scenario happens with 2 of my 3 kits on my SS frame. The first kit will not fit ( it's fit to my PCR which has much wider frame rails) so I can't test all kits.
The only difference I can see ( function or dimensional) from my 75B and SP-01 is the top of the hammer is smoother and the radius is nicer on the SP-01, and the hammer spring appears to be stronger in the 75B. Can the hammer be slowing the slide enough?
Any ideas?
Thank you
-
You mention new, and broken in mags, but does it happen with all the magazines you own?
-
Yes Painter, I have 10 mags, but 5 are for compact, and 5 for full size. All mags are numbered, and 3 of these full size mags have a few thousand rounds thru them, 2 of them are new with this kit. Remember, this is a kit on a full size 75b SS.
I measured the seating depth of the mags, against my SP-01 which does not have this problem, and the 75b sits approx .0025
( twenty five tenths or ten thousandths) of an inch lower in the grip.
I notice no difference between the brand new mags, and the well broken in ones. Though, the fact that I down load them and they work fine does make me consider spring pressure?
Thank you
-
You wouldn't think that 2 1/2 thousandths would matter all that much. :-\
You mention that if you angle the top round just so that it will feed...sometimes.
I'm wondering if there might be something in the frame of the SS, whether by design or manufacturing inconsistency, that changes the angle of the magazine. Have you looked for a casting 'flash', a small piece of extra metal, inside? I'd look lower front, and upper rear.
-
Using the correct depth slide release?
-
I sounds like something is slowing the slide down. Try this. Take the slide out of the conversion body and place it in the frame in its normal position, then load a round in a magazine and insert it. Then stroke the slide and see if the slide catches the rim at the proper elevation and that there is no roughness between the slide and the frame rails. If everything is fine there, then put the gun back together, except leave the recoil spring out, and put the gun in a vice to told it, and stroke the slide with a round in a magazine and see where it hits the barrel ramp. If it hits too low, you can file the front underside lips of the magazine just enough to smooth out the lip and maybe change the angle enough to make it work all the time. You will have to see how the round travels out of the magazine and in to the ramp to see what is going on, possibly comparing to frames which don't have any problems.
Just make sure the surfaces in the magazine that the cartridge comes in contact with are very smooth, as well as the ramp. You can smooth the barrel ramp at the lower side some and not hurt anything, as the firing pin hits on the top side of the chamber. Check in to that also.
Joe
-
Thanks for the replies folks. Painter, I didn't think the .0025 could create the issue either. Joe, thanks for the food for thought. I also wondered if the frame is out of spec too? But I am willing to try your ideas. Protect, I have a nice assortment of slide releases, and I am fairly certain this one is ok. It doesn't drag on the inner rail, or push the mag to the side.
Yesterday, I ran to the range to quickly try a few more items to see if I could make it run better. I took a new mag, and cut a spring down, so far, I have removed 3 full coils, but still no joy. BTW, dropping the slide using the slide release does not change anything.
Again, I can load all mags to 5 rounds, and everything is ok. This frame and kit even will cycle CCI SV, even with temps in the 30's. So to me, it is worth working thru.
Thank you all again for the food for thought. We will fix this.
Happy Thanksgiving to everyone!!!
Rich
-
I went to the range again, and had the same result, so I began to try different things. One thing that seems to work is if I load the mag to 10, close the slide, THEN insert the mag, then rack the slide, it feeds 9 out of 10 times. The one time it fails is the same issue, the round gets stuck at the top of the ramp, directly below the chamber. I am very hesitant to round that area off, as I will be removing area where the rim sits. Maybe I can simply break the edge there?
Now, what I am wondering, is what is different when I insert the mag on a closed slide? As mentioned earlier, the slide stop is then in a fully neutral position to start with( no drag at all on the slide) . Also, maybe the round then gets tipped up, as the slide moves over the rear of the round. Manually tipping the first round seems to work well too. Not perfect, but much better.
I will keep testing..eventually this will be sorted....
Rich
-
Rich,
I'll take some photos of my Kadet barrel ramp this week for you. For now, just wrap some 800 grit paper around a pencil and polsh up the ramp and knock just a little bit of the lip you see off. Then shine it up with some 2000 grit paper. You won't hurt anything. If I can get some comparison photos for you, maybe you can tell if yours is actually different from mine some way.
I can't explain the slide closed versus slide open other than the top round gets pushed down and back some when the magazine is inserted with the slide closed. You should be able to duplicate that with your thumb. I would take the magazine apart, then wrap some 800 grit paper on the end of a cleaning rod, and see if you can smooth out the stamped lips on the magazine where the top round makes contact. Finish with some 2000. The smoother the lips are the better.
Joe
-
Hello all, and Joe, thank you for your interest. Having this problem has made me learn a lot about the CZ in general. What I did the other day, was take all my full size mags, load them to capacity, and let them sit to take a set. Yes, springs do find a set. I have proven this many times over. I also think this frame is on the out edge of acceptable, which may explain why this kit works perfectly on my SP-01, but struggles a bit on my 75B.
Anyway, I made 2 minor adjustments before the range visit yesterday. One is as I said, I left the mags to let the springs set, and second ( which someone said earlier) I swapped out the slide stop for one that had a slightly smaller diameter shaft. I have found variations in shaft diameter of .0015. I used the "thinnest" one, to assure that the slide stop spring would allow the slide stop to fully disengage when I rack the slide back. Also, it introduces a hair more "slop" or clearance for the assembly. Remember, I believe this frame is a victim of tolerance stack.
Yesterday, I used this all on kit #2, which failed the same as kit #3 when installed on my 75. I used kit 2, because after the rear sight fell off ( and my subsequent repair) I converted this kit to a dot sight, using CGW Docter mount, and a Vortex Venom sight. So I needed to sight it in anyway.
285 rounds, and after initial sighting ( mags loaded to 3 for groups), I loaded all mags to 10. It only failed to feed when racking the slide 2x, which is an improvement. If I can get kit 3 to do the same, I will say I am on my way to fixing it.
Joe, I will indeed do the polish of the ramp. The only area that concerns me is the lower portion of the chamber, directly above the ramp. Can I smooth this edge? Not to remove a lot of metal, just to knock down the sharp 90 degree corner?
One more interesting point, is I was able to run CCI SV and Norma Tacs without any cycling issues at all. It was in the high 40s, so I am sure that helped. Either the CCI SV is VERY inconsistent, or the gun is picky, and will only eat SV when it wants?
All in all, I would prefer to run CCI SV and Norma Tac, as I have a fair amount of this ammo, and find it pretty good accuracy wise. I think the Norma is a touch hotter than the SV, but I have no chrono results to back that. I base my statement on the report?
Rich
-
This is what I did to fix the first round feeding issue......comments below pics ;)
(http://i.imgur.com/80VvSwO.jpg)
These are the lobes of the trigger bar that ride in the machined areas of the slide.....these had machining marks that when the slide cycled caught on the much worse machining marks on the slide....see next pic
(http://i.imgur.com/LgOpOVu.jpg)
The profile of the slide shows the notches that the lobes on the top of the trigger bar ride in during the cycling of the slide. It's the bottom surface that needs the attention...see next picture
(http://i.imgur.com/UMUH0gg.jpg)
On the bottom of the slide you can see the machining marks....they look bad but they are very smooth with a slight waviness to the surface, it's kind of how the light is reflecting off the imperfections...but I thought it made it much easier to see the problem. I didn't want to take off too much material between both the trigger bar and slide and have it possibly affect the operation so smooth and non-binding is what I was going for, which when you have the parts out I just slid the surfaces along one another with some pressure to see if they caught at all. The two notches and the ridge in between the notches on both sides of the slide were pretty rough...once those were good then I polished them, always polishing in the direction the part moves naturally, then lube the surfaces, assemble and enjoy!
Hope this helps........I also polished the other contact surfaces of the trigger bar since it was out already.....:)
-
Redlightrich--I finally got some photos for you to compare your barrel to. This barrel works pretty well and only nearly 50k rounds through it. I cleaned it up for you.
(https://photos.smugmug.com/photos/i-kmH9LzZ/0/27dcc110/L/i-kmH9LzZ-L.jpg)
(https://photos.smugmug.com/photos/i-9XrH29v/0/c75f8002/L/i-9XrH29v-L.jpg)
-
Here is what the barrel looked like before I cleaned it up for the photos above...
(https://photos.smugmug.com/photos/i-55bzDPW/0/bf007021/L/i-55bzDPW-L.jpg)
Joe
-
Thank you Joe and Guardian for taking the time to post those helpful pix. I am now experiencing incremental benefits from every step I take.
1) I kept the mags loaded to capacity to let the spring set. They were loaded for over a week now.
2) I smoothed the rails as best I could, using glass as a flat surface, and wet/dry paper, starting at 400 grit, and ending up at 1500 grit. Smooth now!!!
I
3) I reduced the OD of the slide stop pin, to the smallest size of the many slide stops in my collection. I actually removed approx .0015, so it moves very freely.
4) I am much more careful with my slide racking technique. I don't get lazy, and I pull it fully back, and quickly and surely release it.
Yesterday, my range session, I ran 28 full mags thru it. I used CCI 36g HP HV, CCI Tacs, and CCI SV.
Of the 28 mags, 26 fed without issue, and 2 required a second pull on the slide.
I am confident I can get this to 100 percent, if I make the chamber entrance look like Joe's barrel.
I still feel the frame is on the "edge" of acceptable. and I believe the "slop" introduced by the slide stop pin helped a lot.
I will work on the barrel and report back.
I appreciate all the help and guidance!!!
Rich
-
Redlightrich--if loosening up the conversion by putting in a smaller slide stop helped, then the slide must be making contact with something when it is moving. Check to see if the recoil spring receiver on the end of the slide is at an angle and hitting the barrel frame as the slide is moving back and forth. If it is, straighten it back up manually or take it out, remove the stake indentions with a file, clean up the hole, install the spring receiver a little loose so that it can't get stuck at an angle, and see if the slide is not freer to move now. Just another idea to check. My spring receiver is loose and never binds, but one that it straight and peened in won't hit either.
Another thing to check is for contact between the ejector and the slide. The ejector is pinned to the barrel and is very hard and brittle, so you can't bend it without possibly breaking it. I broke one with a cleaning rod once. Remove the recoil spring, assemble the conversion on the frame, and move the slide back and forth and make sure it isn't rubbing or in a bind with the ejector. Just another idea.
Joe
-
Kind of to Joe L?s point about parts binding........I did find on one Kadet slide to host-gun frame there was some binding, that caused me to have to fit the Kadet slide to the frame so it slid in the frame rails smoothly...to determine if you have any binding, just take the Kadet slide all by itself and place it in the frame?s grooves, it should move/slide freely w/o any binding anywhere along the range of movement.......just know once you get everything right, you will be the expert answering questions other folks have ;D
-
Hello all, I feel that the updates are important to help future searchers find answers.
I have taken another .0005 off the slide stop shaft, which eliminated the binding. I am not sure which part is out of spec, ( Barrel Lug or Frame Holes or both) but I did make sure it now goes thru without any binding. Even after removing the 5 tenths, I still have a barrel that is rock solid on the frame. I tested this. So good there.
I couldn't resist my effort to lower my trigger pull, so I installed a 17#MS from Wolff. I now have a 3.5# SA trigger. It is a little creepy, but getting better. I would like to eventually get it to 3.0#. I do realize that when chasing a problem, you shouldn't add more variables. In this case, I didn't get bit.
At the range yesterday, I shot 250 rounds. It was about 32 degrees, and very humid. Occasional snow. The first round manual feed issue happened once, with CCI 36gHP ammo early on. It may have been me being lazy when I racked the slide.
That was it, one time, so it is on it way to being perfect in that regard.
100 rounds of CCI 36g hollows went perfect. Then I pulled out the real test. CCI SV ammo.
Again, all ammo functioned perfectly. No FTE, No FTF, no FTC. Perfect. This gun is very accurate too. My 75 SS model is starting to edge my PCR as my favorite CZ. Maybe I am fond of it due to all I have into it time wise.
After dinner, I decided to clean it up ( against Joe's philosophy!) and I noticed a small bright rub mark on the underside of the slide. It was about .080 wide, and about .200 long, directly behind the bolt recess portion of the slide, but left of center. It appears it rubbed on the 9mm ejector. I am guessing this, as they do line up, but the ejector shows no rub mark? I never seen this mark at all previously, and indeed I did carefully inspect. Maybe the additional slide speed due to the 17#ms allowed it to polish thru? Don't know, but I am very happy with how this kit is now functioning. I am pretty certain that eventually it will manually feed 100%.
As I am a tinkerer by nature, I may get greedy and try to run a 16 or 15# MS. I have bought spare firing pins to alter to achieve my goal.
Thanks to Painter, I now have direction to get pix posted. I have a few that I need to get up here.
At any rate, this kit is now a keeper. I thank everyone who gave input or encouragement.
Merry Christmas
Rich