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Polished my FX Crown .177 Barrel Bore this morning

Hey again Feinwerk,

Did your little "pellet trick" and it sure appears that I did make some positive improvements to the bore. I will know when I can get back out on my target range and shoot some pellets down this nice new clean and smooth barrel :ROFLMAO:

Have a great day,
ThomasT
When you pushed the pellet thru, what attachment if any was on the end of the cleaning rod?.
 
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When I sharpen my chisels and planes for wood working the different colors are used to denote the grit of the compound. I would assume the bore polishes are similar. There's that bugabo word assume so take that info with a grain of salt.
Hello john8

In all my machining work I had a lot of various polishing compounds and like you stated, some were color coded.

ThomasT
 
interesting to hear your liner has a tight spot in the middle. Even though it might not matter too much but still interesting. Out of all my 177 liners I have not noticed a tight spot besides the choke.

I also used JB bore paste but I am lazy so I only polished the choke or last 2 inch of my barrels. Knowing that fx chokes are a little tight I went to town and polished the crap out of the choke on some of my 177 liners and it seems to help with consistency just a little. I saw more improvement with carbon liner sleeve glued on though.
 
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For the life of me, I don't understand this.
Coming from an Aerospace, in Engineering, work background, and an automotive engine building, and a heavy cylinder head porting for a little extra money at home...background.

WHY...would anyone...polish a barrel in segments ?
That's completely, counter intuitive to an evenly polished, with the SAME (or as close as possible) amount of material removed from the length of the barrel.

So, the way I see it, you now have three (or more) barrel i.d. dimensions, and most likely different surface finishes...in ONE barrel.

If I took a barrel to a person/shop that told me, that, that's the way they performed barrel polishing, I'd leave that shop...barrel in hand . The barrel length doesn't matter, to me anyway.

Mike
 
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OK not perfect conditions for testing the Bore Polish Work on the Barrel but here are some early results;
Temperature: 82
Humidity: 91%
Wind: 6 mph

Total number of shots: 88
Maximum distance for a Flyer: .342"

High FPS = 753
Low FPS = 744
Spread = 9
Deviation = 3 ( big improvement here )

I have to say that my concentration was not 100%, it is hard to shoot when it is this hot and I have sweat running down in my eyes. Overall after 88 shots I still had some Flyers but as shown above not near as bad as in the past, so a good improvement here. Consistency in spread, speed and deviation an improvement also. BUT, accuracy was not improved ( not counting the Flyers ), however I made no adjustments to the rifle. With this “new” barrel I believe that it needs to be re-tuned to achieve maximum accuracy, ( Regulator, Hammer Spring, and Pressure ) to use the same ammo ( JSB Exact Monster 13.43 ). Attached are two photos showing typical 5-shot groups and the max flyer out of the 88 shots.

Oh yeah, Tom @tcarlson777, you are correct about cleaning the barrel, after the 88 shots I pushed a cotton swab just one time down the barrel. I opened the breach and put a light in and looked in the muzzle and it looked like a mirror :)

I hope sharing this information will be of some benefit to others, and it has been fun for me.

Be safe and have a great day,
ThomasT

Test-73-1.jpg

Test-73-2.jpg
 
Hello everyone,

After over 150 rounds of various pellets shot through the rifle it is as I had expected, the New Polished Barrel needed to be re-tuned. It’s almost like this is a new gun and the polishing work changed the dynamics of the barrel. I went back to my old charts where I had tested over 20 different pellets and choose 4 to test with the new barrel. Turns out that the JSB Heavy 10.34gr shot the best with no flyers out of 25 shots, see the attached photo. That is 5-shots per round at the five individual targets. The Crosman Domed 10.5gr shot an almost identical pattern with no flyers. I have made one adjustment to the rifle and I moved the Hammer Spring Setting up to 16 but left the Power at Medium and the Pressure at 120. Again I hope this information will be of some help.

Have a great 4th of July,
ThomasT

FX Crown Polish Plus-2.jpg
 
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@ThomasT,
Those groups are looking really good. One of the things I would have expected, and was verified by your data, was a reduction in the standard deviation of your velocities after polishing. At this point you can try adjusting your velocity up and down to find an even sweeter spot where your groups shrink with the same pellet.

Just for grins you can shoot a couple of pellets into a 5 gallon bucket of water, recover them, and look at how smoothly and evenly each pellet is engraved.

I think the action on the Crowns evolved from the Royale 400. I believe the same block (as the Royale 400) is used in the FX independence. I have one of those in 22 caliber and the cocking is very smooth. I try to work the bolt slowly and consistently for each shot to try to reduce flyers. I never jam the pellet home rapidly but slowly and deliberately each time.

Have fun and enjoy that rifle! I have yet to add a 177 cal PCP to my arsenal but I'm thinking about it someday.

Regards,
Feinwerk
 
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Hello Feinwerk,

I did play around with the Power and Hammer Spring settings quite a bit but did not change the Pressure. I tested 4 different pellets and found that the Med and up to 16 on the Hammer turned out to be the best settings. However the JBS Monster 13.43 pellet that I have been shooting came in a distance 3rd with the JBS Heavy 10.43 and the Crosman Domed 10.5 a first and second. This morning I shot four of the 30 Yard Challenge targets and on my last target I shot a 199 with 18xx's and zero flyers. I believe the New Barrel is now "seasoned".

Now I am not very careful when loading a new pellet as you described, so I will apply you process from now own, thank you for this good advice (y) .

Have a great day,
ThomasT
 
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I have a First gen. Crown .177 with Huma reg and 600 mm superior barrel.
You should try the QYS 9.56 streamlined or the H&N Baracuda FT.
Both shoot extremely well out of my crown at 850 to 900 fps.
The skirt on the QYS are thicker and by that more stable.
The H&N Baracuda FT is also with thin skirts but H&N uses a harder lead mixture so they are still reliable,.
My Crown also shoots the JSB heavy quite fine. But JSB lead is soft and it is easier to get fliers with Heavies.
Your 120 bar pressure is high for heavies. I use 100 bar. to get 900 fps.
 
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I have a First gen. Crown .177 with Huma reg and 600 mm superior barrel.
You should try the QYS 9.56 streamlined or the H&N Baracuda FT.
Both shoot extremely well out of my crown at 850 to 900 fps.
The skirt on the QYS are thicker and by that more stable.
The H&N Baracuda FT is also with thin skirts but H&N uses a harder lead mixture so they are still reliable,.
My Crown also shoots the JSB heavy quite fine. But JSB lead is soft and it is easier to get fliers with Heavies.
Your 120 bar pressure is high for heavies. I use 100 bar. to get 900 fps.
Good morning engfred,

Thank you for this information. I have some of the H&N in stock so will give them a try in the morning. I have run all kinds of test with various pellets with this rifle but never at 100 bar setting. I turned it down to 110 and up to 140, so I will give the 100 bar a test run.

Thank you again and have a great day,
ThomasT
 
I have a First gen. Crown .177 with Huma reg and 600 mm superior barrel.
You should try the QYS 9.56 streamlined or the H&N Baracuda FT.
Both shoot extremely well out of my crown at 850 to 900 fps.
The skirt on the QYS are thicker and by that more stable.
The H&N Baracuda FT is also with thin skirts but H&N uses a harder lead mixture so they are still reliable,.
My Crown also shoots the JSB heavy quite fine. But JSB lead is soft and it is easier to get fliers with Heavies.
Your 120 bar pressure is high for heavies. I use 100 bar. to get 900 fps.
Hello again @engfred,

I just checked and have ever Baracuda but the FT. The dealer shows having a 4.50 and a 4.51 in .177 cal in stock, which one are you shooting? Also what Hammer Spring setting?

Thanks
ThomasT
 
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