Author Topic: NOW I have some targets worth showin' to Europe!  (Read 1247 times)

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Offline Joe L

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NOW I have some targets worth showin' to Europe!
« on: April 08, 2021, 04:11:44 PM »
I went to the range on Wednesday but I didn't get the MTR cleaned well after Tuesday and the target results were inconsistent.  So, on Wednesday night, I spent some quality time with the JB Bore Paste and VFG abrasive pellets, and got MOST of the carbon ring at the chamber removed, using three pellets. 

I went back to the range this morning and decided to shoot three shot groups to conserve ammo, as I was experimenting with a DIY tuner, just for my own education.  Here is a video of 4 good groups from today. 



After 60 rounds or so, the accuracy went south again, so I packed up and went home.  Maybe 5 or 6 pellets tonight and I can get the rifle clean enough so it will hold accuracy for 100-150 rounds or so.  I attribute the chamber carbon ring sensitivity to the tight CZ chamber dimensions that also help with the accuracy.   I never expected to see groups this small from a production .22LR on a windy day. with a pistol shooter handling the trigger.

The borescope was actually helpful this time, as in confirming that, yes, there was a carbon ring just upstream of the lands at the chamber, and yes, most but not all of the carbon was removed prior to heading to the range this morning. 

This is fun.  This is not easy.

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

Europe

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Re: NOW I have some targets worth showin' to Europe!
« Reply #1 on: April 08, 2021, 05:12:43 PM »
Very nice. As you can see, the whole problem is to stay in the 0-0,5 MOA range for a 5-shot or 10-shot group. A 0-0,5 MOA 3-shot group is within our reach if we do our thing.

skin

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Re: NOW I have some targets worth showin' to Europe!
« Reply #2 on: April 08, 2021, 07:14:20 PM »
 Way to go! Nice shooting

Offline Joe L

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Re: NOW I have some targets worth showin' to Europe!
« Reply #3 on: April 08, 2021, 07:46:37 PM »
Very nice. As you can see, the whole problem is to stay in the 0-0,5 MOA range for a 5-shot or 10-shot group. A 0-0,5 MOA 3-shot group is within our reach if we do our thing.

Yep, I felt like I was cheating shooting only 3 shot groups, but I wasted 150 rounds on Wednesday, so had to "conserve" today!  The consolation prize was the two three shot groups on the dot.  I think the wind changed slightly, offsetting the second group to the left just slightly from the 1st group. 

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

Offline huskerlrrp

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Re: NOW I have some targets worth showin' to Europe!
« Reply #4 on: April 08, 2021, 08:28:30 PM »
I bought some Slip 2000 and use it in rifles when accuracy becomes an issue. I plug the bore and let it soak, but have also used a contact soak, scrub and re-soak method. The only thing that concerns me is rust, so I make sure I get some breakfree in everything afterwards. I find it easier than using an abrasive like JB.

For what it is worth, I don't have a carbon problem in my Anschutz rifles with Hoppes #9 as a cleaner. 

skin

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Re: NOW I have some targets worth showin' to Europe!
« Reply #5 on: April 09, 2021, 01:34:28 AM »
 What type tuner are you using and how well does it work?

Offline Joe L

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Re: NOW I have some targets worth showin' to Europe!
« Reply #6 on: April 09, 2021, 06:34:38 AM »
What type tuner are you using and how well does it work?

One, then two 7/8" id Amazon steel shaft collars roughly 0.4"-.5" from the end of the non-threaded barrel.  I use a depth micrometer to measure the distance from the muzzle and have been moving the collars in about 0.010" increments to see the effect.  The weight of the two collars is about 6 ounces, similar to a proper aftermarket threaded barrel tuner.  The rifle shoots pretty well without any tuning, but I can make it shoot terribly WITH the collars in certain positions.    The shots in the video above were from the o.510-0.535" range, but the accuracy went south before I could confirm repeatability.  So I removed the weights and confirmed the barrel accuracy was nil with or without the weights, so packed up and went home. 

On Tuesday, with one collar and only a caliper to crudely measure position, the most interesting result I got was good results using the Norma Match ammo that I have always used in my Kadet at 50 yard bullseye matches.  That ammo simply would not shoot well in the MTR, as in 2-3" at 100 yards, compared to 1" with the SK Rifle Match.  I put the single collar on and started getting around 1" with the Norma Match.  Quite surprising.  And seemed repeatable, but I didn't do any fine tuning.  When I removed the shaft collar, the Norma group went back to 2".  So, in theory at least, it may be possible to use a weight to make otherwise good ammo a better match for a particular rifle, with the resulting group size variation proportional to the SD of the ammo in use. 

As Europe pointed out, consistency is what matters.  Five and ten shot groups tell the real story, three shots are good enough maybe for experimentation to show me roughly when the collars were in a favorable position...or when the barrel is getting fouled again. 

I'll make a video on the DIY tuner after I am convinced the effort is really beneficial.  With the ammo shortage, I'm not in the mood to blow through another 200 rounds for a 1/2" improvement on one type ammo that may change slightly in the next lot. 

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

Offline M1A4ME

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Re: NOW I have some targets worth showin' to Europe!
« Reply #7 on: April 09, 2021, 07:19:54 AM »
Joe, do you see that carbon ring on all ammo you've shot through that rifle?

I'm curious about it.  I've never shot a lot of ammo through a .22 rifle in a session but I've shot a few hundred rounds through my old Ruger Mk1 5.5" many times back in the early 80's and never saw a drop off in accuracy during an afternoon of fun. 

How do you determine it's carbon?  I was wondering if you use a cleaner that that shows up different on the patch depending on what the patch carries out of the barrel.  Like the BTE showing up bluish green for copper and dark black for lead.
I just keep wasting time and money on other brands trying to find/make one shoot like my P07 and P09.  What is wrong with me?

Offline Joe L

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Re: NOW I have some targets worth showin' to Europe!
« Reply #8 on: April 09, 2021, 08:14:54 AM »
M1A4ME--I haven't shot much ammo other than the SK through this rifle.  It could very well be related to the ammo, but, if so, it would be a pretty common problem.  I think a lot of benchrest shooters clean their barrels or at least the chamber area between target sheets to remove the slight buildup of however many rounds they fire per target sheet. 

I used the Teslong borescope to check it when I got home and could see lots of buildup, especially around the chamber/leade area.  Last night, it cleaned out just with a nylon brush and Kroil, so I didn't use the pellets.  I could see bare metal again.  I don't remember seeing any similar carbon buildup on the Kadet using the Norma ammo, but the Kadet will start malfunctioning before the accuracy falls off.  I have to clean it every 400-600 rounds no matter what, and I've gone to cleaning it every range trip since moving to the humid climate anyway.

The lands and rifling clean up very easily in the hammer forged CZ barrel, but cleaning the rough Savage barrel was a nightmare with all the machining roughness. 

I ASSUME the residue is carbon, but it is more likely a combination of primer residue/carbon/powder combustion products.  Carbon to me is a catch-all term for "combustion residue". 

Centerfire pistols are simpler and more repeatable!  Rimfire rifles are challenging, to put it mildly.  At least the CZ MTR is actually fun while being challenging. 

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

Offline Joe L

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Re: NOW I have some targets worth showin' to Europe!
« Reply #9 on: April 10, 2021, 10:09:36 AM »
Enough experimentation on the MTR.  Here's what I've concluded from messin' with the Amazon shaft collars...

1.  Both the POI and the group size changes when the weights are moved on the barrel. 

2.  The adjustment is tough to do with the split collars and a depth mic.  The adjustment is too sensitive, as in a 0.030" range between "bad" settings to find a "good" setting.  Can't do it repeatably by hand.  Need a threaded adjustment mechanism...in other words, a commercial tuner. 

So I ordered a Harrell's slip on for the CZ barrel OD, and put the rifle to the side until it arrives.  When it arrives, I'll try the following...

a.  See if I can find a sweet spot for my favorite bullseye match ammo, the Norma Match.  This has never shot well in the MTR prior to trying a barrel weight.  Record the setting for future reference when I can buy a large quantity of the Norma Match ammo (for the Kadet). 

b.  Find a setting which works well with the SK Rifle Match that I have and assume I can fine tune for different lots of that ammo when available. 

I'll consider this experiment a success if the average 5 shot group size shrinks by 1/4 to 3/8" from the current average of just over an inch, on a calm day at 100 yards.  In other words, 3/4-1"  groups, every day, with an occasional 0.5".

Buy some Lapua Center X or Midas+ and repeat, when both ammo and funds are available.

This project should keep me out of the bars and whore houses for a while.

Joe 

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

Offline Joe L

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Re: NOW I have some targets worth showin' to Europe!
« Reply #10 on: April 15, 2021, 08:18:14 AM »
I ordered the Harrell's rimfire tuner late last week and received it on Wednesday.  It was bored slightly oversize for the 0.865" MTR od barrel and slipped right on and tightened down perfectly using the two small collar clamp screws and an Allen wrench.  The adjustments are smooth and have a good detent but no way to lock it in place, so I will have to be careful getting the rifle in and out of the bag.  It cost $158 including shipping to Texas and including the bore cut to match my barrel.  Seemed like a good deal to me.  I am quite happy with the tuner from a manufacturing and customer service standpoint. 



I will get to try it next week, I hope.

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

Offline timetofly

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Re: NOW I have some targets worth showin' to Europe!
« Reply #11 on: April 15, 2021, 09:46:38 AM »
Awesome shooting Joe. When I finish recovering hopefully I can come close to that at 50 yRDS WITH MY 455 VARMINT.
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