The Full Monty Barrel Prep!

[Michael]

A little bird mentioned that he used Kroil as the first step in barrel prep.

Supposedly it separates loose metal from the barrel. So I gave it whirl today, and it worked great. I use a Dewey graphite rod, a brass jag, and tightly sized patches for each step.

1. Kroil soak inside of barrel
2. JB Bore Paste 200 strokes (new patch every 50 strokes)
3. Kroil clean (as many patches as needed to remove JB Bore paste)
4. JB Bore Bright 200 strokes (new patch every 50 strokes)
5. Kroil clean (as many patches as needed to remove JB Bore Bright)
6. A few dry patches to remove Kroil
7. A few wet patches of CLP, Gunzilla, or Balistol to lube & protect
8. 1 dry patch to finish

This is the method I'll use to prep brand new or "problematic" barrels moving forward. But for all subsequent cleanings I feel confident that the Patchworm bore cleaning kit will get the job done.

-Michael

 

[2D1C]

That Kroil works great as a penetrating oil as well!

 

[Centercut]

Great regimen. Thanks. I think I'll start doing that also... 

Mike

 

[Michael]

How do you know when you've used enough abrasive/polish/repetition?... when the barrel gets too hot to touch!

 

[2D1C]

LOL

 

[Revoman]

Okay Michael, I have a cuppla questions for ya;

When ya ran the 200 strokes with the bore paste, did ya have the muzzle up against something so that the abrasive stayed away from the crown and was pulled back through? How'd the jagged patch pull back through, was it so tight that is didn't come off on the upstroke? I have that same Dewey rod and find that its pretty bendy/unstable if trying to push something that tight down the barrel from the starting position. Have the same issue? When ya "soaked" the barrel with Kroil, did ya cap both ends and leave the Kroil in there for awhile? How long? Or did you simply Kroil a patch and let it soak for a bit?

Okay, okay, I said a cuppla questions, I lied!

Thanks for any insights!

mike

 

[qball]

WOW! Very nice process you developed there, inside of your barrel must be a hall of mirrors fit for king of France! Come to think of it I haven't cleaned my barrels in.....basically forever. 

 

[Airgun-hobbyist]

Okay Michael, I have a cuppla questions for ya;

When ya ran the 200 strokes with the bore paste, did ya have the muzzle up against something so that the abrasive stayed away from the crown and was pulled back through? How'd the jagged patch pull back through, was it so tight that is didn't come off on the upstroke? I have that same Dewey rod and find that its pretty bendy/unstable if trying to push something that tight down the barrel from the starting position. Have the same issue? When ya "soaked" the barrel with Kroil, did ya cap both ends and leave the Kroil in there for awhile? How long? Or did you simply Kroil a patch and let it soak for a bit?

Okay, okay, I said a cuppla questions, I lied!

Thanks for any insights!

mike

A polished crown (from the JB cutting compounds and patches exiting) is not detrimental to accuracy, so long as that crown is square with the bore still. However, re-crowning the barrel may be necessary if it shoots in a particular direction, indicating it is not square. After squaring the crown to the bore I polish the cutting marks out of it to shine like the bore, and I have gotten good results every time doing it this way.

 

[Airgun-hobbyist]

How do you know when you've used enough abrasive/polish/repetition?... when the barrel gets too hot to touch!

That thing should shine! Got a bore scope? This thread could see picture of that as well.

 

[Michael]

Okay Michael, I have a cuppla questions for ya;

When ya ran the 200 strokes with the bore paste, did ya have the muzzle up against something so that the abrasive stayed away from the crown and was pulled back through? How'd the jagged patch pull back through, was it so tight that is didn't come off on the upstroke? I have that same Dewey rod and find that its pretty bendy/unstable if trying to push something that tight down the barrel from the starting position. Have the same issue? When ya "soaked" the barrel with Kroil, did ya cap both ends and leave the Kroil in there for awhile? How long? Or did you simply Kroil a patch and let it soak for a bit?

Okay, okay, I said a cuppla questions, I lied!

Thanks for any insights!

mike

• Soak - I plugged the muzzle and filled the barrel with Kroil and let sit for a few minutes.
• I use a .22 jag & Dewey 1.5'' round patches. They're tight enough that I use a rubber mallet to tap the handle and get the patch started (then push by hand to ensure a smooth transition of the coupling into the lead in). 
  
• I secure the barrel horizontally in a vise 
  
• I polish the muzzle/crown as well. I set the depth by holding a block of wood on the muzzle and push the rod till it hits the wood. Then ditch the wood and push the patch/jag past the crown about 1/4''. Then I clean the rod near the lead-in and wrap some painters tape onto the rod that acts as a bumper/stop. 
  

 

[Revoman]

Jeepers Michael!!

Thanks so much for the extra effort in answering my questions. Hopefully they will answer others as well.

I'm gonna do this tonight!

mike

 

[elh0102]

Interesting process Michael. Thought about doing it, but decided......naaahh, think I'll stick with a few pull-throughs and a glass of bourbon (for me). If the barrel is a real mess, a second glass might be required!

Seriously, I've had only a couple of barrels that seemed to benefit much from polishing. A couple I thought would benefit had more serious problems and ended up in the trash. But I know it's a proven process and I don't question its value in certain instances.

 

[Michael]

Interesting process Michael. Thought about doing it, but decided......naaahh, think I'll stick with a few pull-throughs and a glass of bourbon (for me). If the barrel is a real mess, a second glass might be required!

Seriously, I've had only a couple of barrels that seemed to benefit much from polishing. A couple I thought would benefit had more serious problems and ended up in the trash. But I know it's a proven process and I don't question its value in certain instances.

The bourbon may loosen up some of the material but wouldn't drink it after that!

 

[Tenn_Bootlegger]

Airgun barrels are made of mild steel as are muzzle loading rifles. Care must be taken when applying compounds that have a abrasive grit incorporated in them. my way of careing for an airgun barrel is this use the correct size mop. Lightly apply Mobile-1 10W30 motor oil to the mop ;it is a synthetic oil. It penatrates the steel and fills the surface of the steel in such a way as to keep dirt and grime from becoming inbeded in the surface. After shooting I simply run the mop down the barrel and thats it. The mop get the dirt , so just wash the mop. It also lowers the friction between the pellet and the barrel.

 

[heavy-impact]

You don't want a mirror finish because it's too much surface area and causes more friction.

 

[8thman]

Thanks MICHAEL 

 

[Michael]

You don't want a mirror finish because it's too much surface area and causes more friction.

Please elaborate because this logic does not compute... a surface that is smooth and polished has more friction than a surface that is rough, unrefined, or textured?

 

[Centercut]

You don't want a mirror finish because it's too much surface area and causes more friction.

Please elaborate because this logic does not compute... a surface that is smooth and polished has more friction than a surface that is rough, unrefined, or textured?

+1 here... I'd like to hear that explanation also. The smoother the surface (RHR), the less the Coefficient of Friction (μ), so as μ decreases, so does Force max with a constant applied Force Fn. (Fmax= μ Fn). Maybe there is more to it?

 

[nervoustrig]

The popular analogy is drawing a crayon across a piece of paper (textured surface) versus drawing it across a piece of glass (polished surface). You’ll feel more friction against the polished surface. Or the same thing with a rubber eraser.

However it doesn’t seem to play out that way with barrels from what I’ve seen. I don’t know if it has to do with the materials (lead against steel), the elasticity of an eraser versus ductility of lead, the nature of the forces (pressing the crayon against the glass the whole time, versus lead being swaged to the barrel profile and then experiencing only minor friction), some combination of the three, or another cause altogether.

However even in the case of slugs rather than pellets where friction is much more of a factor, Mike (knifemaker) has done extensive testing and found a polished surface extends cleaning intervals substantially. Granted, one will almost always be using lubrication of some kind on slugs. Try smearing a little silicone oil on a piece of glass and then drag a crayon over it.

 

[Franklink]

You don't want a mirror finish because it's too much surface area and causes more friction.

Please elaborate because this logic does not compute... a surface that is smooth and polished has more friction than a surface that is rough, unrefined, or textured?

+1 here... I'd like to hear that explanation also. The smoother the surface (RHR), the less the Coefficient of Friction (μ), so as μ decreases, so does Force max with a constant applied Force Fn. (Fmax= μ Fn). Maybe there is more to it?

Not sure how it applies to airgun barrels but a buddy back in high school had a shuffleboard table in his families rec room. When we played, there was "shuffleboard wax" that was sprinkled on the surface where the pucks glide. That shuffleboard "wax" sure seemed an awful lot like sand. And it dang sure made the pucks glide more easily. I'm guessing it relates back to the percentage of surface area that is in contact with each other. Ie, the puck is riding on top of the particles of sand and travels with less resistance than it would if it its full surface area is in contact with the playing surface. 

Not sure that there is any applicable use of the concept in an airgun barrel though.