Author Topic: Kadet accuracy at 50 yards  (Read 712 times)

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Offline Joe L

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Kadet accuracy at 50 yards
« on: January 04, 2019, 03:25:00 PM »
Separate thread for the Kadet since temperature of the gun and ammo is not the problem.  Warmed up considerably here since Tuesday, so today I returned to the range with some 1200-1235 fps 40 gr ammo, along with my standard velocity Norma Tac22 and Match ammo.  Bench rest at 50 yards.  50F, 10 mph wind. 

Federal AutoMatch --roughly 8" 10 shot groups, twice
Norma Match                      3-1/2" groups, twice
CCI MiniMag                       3-1/2" groups, three times
Aguila Super Extra              3" best, 4" twice

Next, I put up a B-8C target at 50 yards and shot 20 rounds of the Aguila Super Extra, doing the best I could, resulting in a 3-1/4" 20 shot group.  So the Aguila is consistent. 

You might think these are good results.  Not from this gun.  About twice the typical group size.  But now I have plenty of ammo choices that cycle the gun fine in cool, not cold, weather, so next is a very thorough cleaning of the barrel and polishing of the chamber.  I remember having to do this once 2-3 years ago to restore the usual close to 1" at 50 yards accuracy.  I am not concerned over the subsonic/supersonic considerations at this point. 

I will probably spend some time Saturday cleaning the barrel and then shoot it again on Sunday.  With video, I hope. 

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #1 on: January 05, 2019, 11:43:04 AM »
Took a lot of VMG pellet patches, Kroil, and JB Bore compound, but I finally got the barrel and chamber pretty clean.  I let it go too long, that's for sure, as I scoped it prior to cleaning and the chamber and leede area were crudded up pretty good, especially in the "black ring" area of the chamber at the end of the casing.  The leede area is pretty rough so I don't know if I will have good results on Sunday or not.  The barrel may really need replacing. 

If the chamber cleaning reduces the recoil force needed to extract the spent case from the chamber, that alone will be an improvement.  I think I am going to order a barrel if the Sunday results aren't back to normal again.  Probably easier than just cleaning the thing more often like normal shooters would do.

 :) :)

This is fun.  This isn't easy.  And it smells bad, too. 

Joe   
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #2 on: January 05, 2019, 12:02:31 PM »
I looked at my own video from 2016 where I cleaned the Kadet and then went to the range and shot it at 50 yards from a rest.  It took 30 rounds to settle down vertically.  I will have to allow for that on Sunday.  But I am going to start with the Tac 22 and see if the gun cycles OK before I go to the HV ammo.  If the gun cycles OK on SV, then I will continue on with that for maybe 50 rounds total, then go back to the accuracy check of the Aguila hv, since I have so much of it!  But I will give it 50 rounds to settle in also. 

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline painter

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Re: Kadet accuracy at 50 yards
« Reply #3 on: January 05, 2019, 12:05:30 PM »
Is the leade eroded, as well?
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Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #4 on: January 05, 2019, 02:43:30 PM »
Is the leade eroded, as well?
I think so, based on what I can see with my cheap low resolution 'scope.
Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline painter

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Re: Kadet accuracy at 50 yards
« Reply #5 on: January 05, 2019, 04:51:00 PM »
Is the leade eroded, as well?
I think so, based on what I can see with my cheap low resolution 'scope.
Joe
Well...you do have a 'few' rounds through it. ;)

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Offline steel

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Re: Kadet accuracy at 50 yards
« Reply #6 on: January 06, 2019, 09:10:37 AM »
I hope everything works out with your Kadet barrel.  I would like to see you break 100K rounds in it.  If you decide to re-barrel your Kadet, you should contact CZ.  CZ would probably want to put it on display as a testimonial or at least do some tests to see what they are doing right.

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #7 on: January 06, 2019, 11:18:49 AM »
Just got back from the range after cleaning the barrel as thoroughly as possible on Saturday.  Feeding problems gone, even with the SV Norma Match ammo, but the accuracy just isn't there.  It is burned out.  I just ordered a replacement.  But I will keep the old one to look at if and when I get access to a real borescope.  I could see the leade (leede?) area was pitted with my El Cheapo borescope.  Looked good for about 20 rounds, then accuracy fell off again to what it was before I cleaned it.  Barrel is just too rough, I'm thinking.  New barrel will be in this week, if CZ-USA can catch up from the holidays. 
Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline eastman

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Re: Kadet accuracy at 50 yards
« Reply #8 on: January 06, 2019, 12:06:41 PM »
the combination of barrel leading + powder fouling + a little atmospheric moisture (doesn't take much) can lead to electrolytic corrosion. Common source of pitting in .22 rimfires.
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Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #9 on: January 06, 2019, 01:32:02 PM »
Eastman--yep, that is what I am thinking.  I removed the barrel and the ejector from the original barrel without breaking it (the ejector is brittle) so I should have everything I need when the new barrel arrives.  After cleaning up the old barrel and looking at it again, I am still not certain what the damage is that might be messing up the bullet as it starts its journey down the barrel.  I probably should have looked at it before running some hard patches and JB Compound down the barrel.  Might have removed a chunk of lead that got caught in a pit, for example.  If the new barrel gets me back to 1.5" or so, then I'll study the old barrel in detail. 

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #10 on: January 06, 2019, 01:37:05 PM »
I went out at sunrise and it was cloudy and overcast, so kinda dark.  It was't hard to see the dot, it was hard to see my aim point on a brown paper background.  Last thing I tried was a B-8C target which has a dark bullseye large enough that you can see whether the dot is centered in it or not.  I am kind of used to this target at 25 yards.  At 50, it is plenty big.  Even using this target, I had some shots out of the black and there is no way I moved the gun that much, so, out with the old barrel.

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #11 on: January 09, 2019, 07:26:50 PM »
I got the new barrel and a Lyman borescope on Tuesday, and installed the barrel this afternoon but won't get to shoot it until Thursday.  Can't wait. 

For anyone thinking they want to replace a Kadet barrel, here are some notes. 

1.  The barrel comes bare.  You will have to remove the ejector and ejector retaining pin from the old barrel and very carefully re-install on the new one.  Be very careful as the ejector is very brittle and will snap easily. 

2.  The barrel is not drilled for the retaining pin that places it in the conversion slide.  You will have to set the location in the conversion slide, and then drill the hole.  I had a drill press and a #30 drill, and I think it is OK.  I reused my old retaining roll pin because it was not very old anyway.  It must be a 3mm roll pin, about 20 mm long.  Roughly.  I have new ones but I can't remember the size. 

3.  I had to fit the barrel lug width by hitting the left side a few strokes with a file, just like you would have to do with a new Kadet.  No change to the tabs on the conversion slide, however. 

4.  The new barrel looks smooth and shiney with the naked eye.  With the borescope, the machining looks pretty rough but that is due to the magnification of the borescope.  There were no burrs or "bad" machining and the barrel was clean when I got it.  As far as I know, it looks exactly like one would look if it came in a new gun. 

Now for the old barrel.  With the borescope, the entire barrel bore looks rough, probably due to corrosion.  The chamber was very bad.  I could not see where the rifling started like I could on the new barrel due to the sharp edges where the reamer was tapered.  Note that I have no experience analyzing .22 pistol barrels.  I am going to look at the Ruger and then look at the new barrel after I put 100 rounds or so through it and see for myself how different they are.  I am also going to take a look at my 9mm and .45 barrels.  I'm bound to learn something, probably to clean them more frequently! 

More later after I actually get to shoot through the new barrel on Thursday.    I am pretty sure it will be under 2" after 20 rounds and close to 1" after 50.  I hope.

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #12 on: January 10, 2019, 02:46:35 PM »
I went to the range at sunrise and put 100 or so rounds through it before heading to the office.  Gun cycles fine now with SV ammo, so the new chamber isn't dragging on the spent casings like the old one.  I put a target up at 25 yards and shot 10 rounds, without changing the zero on the red dot, the hits were a few clicks off right and down, so I know I got the barrel pinned in the slide correctly.  No misfires or light hits or failure to feed issues.  That's a relief. 

Eventually got to 50 yards with good results and then shot four 25 yard timed fire targets, again with excellent results and no problems.  So I think my worn out (or most likely, corroded) barrel and rough chamber were the culprits. 

More later after I clean and 'scope the new barrel.  Yes I am going to clean it.  But just the barrel.

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline Joe L

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Re: Kadet accuracy at 50 yards
« Reply #13 on: January 11, 2019, 02:08:33 PM »
Another 100 rounds of Norma Tac22 at 25 yards, then Match at 50.  New barrel is coming around.  I was able to shoot 95-96 timed fire targets and 11 of 18 rounds in the 10 ring at 50 yards from a wrist rest, in a medium cross wind.  No failure to fee but not cold today, just low 50F temp.  I cleaned the barrel with Kroil and some tight patches and then ran a pellet with some JB bore paste up and down the bore, cleaned all of that out, and then 'scoped it.  The tooling marks from the reamer have smoothed out, the lands look perfect, no rough spots, bore looks excellent, at least to me.  A little carbon in the throat area but no build-up.  That is what I have to watch for, I think, and keep down, now matter what.  I am going to 'scope and clean this barrel after every range trip and see if I can keep the chamber area clean and smooth for a change.

My opinion is that this barrel smoothed out and is stable after about 200 rounds, perhaps much less, like close to 100, based on the observation that I didn't have any bad results today at all.  I was not steady myself but I was able to call all the bad shots during timed fire practice, and that means the bullets are hitting where the dot was pointed when the gun went off. 

No more testing.  I am going to just go back to my regularly scheduled bullseye practice sessions, now that I know the gun is back to 100%.  Time to get the shooter back to 100%.  May take a few weeks, LOL. 

I may try to do a borescope video comparing the old and new barrels on Saturday.  Maybe.

Joe
CZ-75B 9mm and Kadet, 97B"E", two P-09's, P-07, P-10C, P-10F

Offline painter

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Re: Kadet accuracy at 50 yards
« Reply #14 on: January 11, 2019, 02:44:43 PM »
Glad it's all sorted Joe.

I'd be curious to see the comparison between a new, and a 50K round barrel. It would also be interesting to see the difference regular barrel cleaning makes to the longevity.
I had the right to remain silent...

but not the ability.