Do Not Break in your Barrel

[hogpatrol]

JB Bore Cleaner on a hand turned patch will remove machine marks? Wow. How long does that typically take?
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brians356 Barrels after chambering done by a good smith will not have big chunks in the lands they are tiny. All I do is smooth them out a little before I fire a single shot. Works for me, if you don't agree then skip this page. I suppose when you get your new barrel you just go out and shoot it just the way it is. So my question to you is how long do you take to clean a barrel, just till the patches come clean. And if you don't clean with the use of a bore scope, you should! A few think we are lying about what we do, I don't!
Oh and try dragging your brush back an fourth though the bore and see how long it takes to make it oblong.

Joe Salt

Everyone has their pet methods, fine emery, steel wool, JB, Iosso, etc. I chambered a .17 Fireball and I do the same as Joe only with a battery drill motor for a few seconds. Took it to the range yesterday. First shot, cleaned it three patches of BBS, dry patch then some Sweets. Let sit for 15 minutes, no copper. Repeated this process for the next four shots, not a hint of blue. Barrel is a Pac-Nor super match, 3 groove featherweight. After cleaning, I always shoot the first shot wet with Hoppe's 9. YMMV.

 

[msinc]

Not all lapping is the same between barrel makers.

Neither is the steel or the basic machine work. I believe that one of the reasons there is so many opinions and differences of information on this topic is because there are so many "unseen" variables.
Many moons ago, when I worked as an automotive machinist, there was this big raging debate over types of piston rings and the required finish in the cylinders to make the rings break in and run the longest/make the best seal/produce the most power/use the least oil/ have the least blowby, etc., all in the shortest time.
One day, a salesman showed up at the shop. He was selling a device called a "surface profilometer"....also known as a roughness tester. He had a bunch of photos taken with a special microscope that showed what looked more like the surface of a plowed field. These were actually taken of an engines freshly bored and honed cylinders.
He demonstrated this little {also rather expensive at $2k back in the 80"s} device by setting it in a "finished" cylinder bore and turning it on. A little stylis came out and dragged itself across about an inch worth of bore, then a number appeared in the display and it turned off. He then showed us the corresponding photos and it was bad.
The point being; we learned that, depending on a lot of factors, several finished cylinders all machined with the same equipment could look like they were identical to us. Yet, these "same" cylinders had a very different surface profile {roughness} at the minute level of required finish.
A barrel is like a woman....you really have to look hard to find out what you got!!! And you probably wont like what you see....better to just get one from Mexico!

 

[Brians356]

JB Bore Cleaner on a hand turned patch will remove machine marks? Wow. How long does that typically take?
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brians356 Barrels after chambering done by a good smith will not have big chunks in the lands they are tiny. All I do is smooth them out a little before I fire a single shot. Works for me, if you don't agree then skip this page. I suppose when you get your new barrel you just go out and shoot it just the way it is. So my question to you is how long do you take to clean a barrel, just till the patches come clean. And if you don't clean with the use of a bore scope, you should! A few think we are lying about what we do, I don't!
Oh and try dragging your brush back an fourth though the bore and see how long it takes to make it oblong.

Joe Salt

Untwist thy knickers, Joe. Why the dissertation? All I asked was how long does removing machining marks take you by hand with JB on a patch.
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[Joe Salt]

All I asked was how long does removing machining marks take you by hand with JB on a patch.
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Well if your looking for an easy way you will have to find another alternative. I probably go at it for maybe half hour 45 min just have to keep cleaning and looking to see if there is any progress. Then clean everything out with Kroil then go shot a few and clean again. the copper should get less and less as you shoot.
Hope this helps. Because I not doing it for you. Its a pain in the ass, but if you don't want a lot of copper try it. as of this point I haven't found a better way.

Joe Salt

 

[Barlow]

If I ever get my new barrel installed (257AI) I'm going to do Joe's regime. A also use Eezox in all my barrels, rifles, pistols and shotguns. Barlow

 

[JRS]

If I ever get my new barrel installed (257AI) I'm going to do Joe's regime. A also use Eezox in all my barrels, rifles, pistols and shotguns. Barlow

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

 

[msinc]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

That can be a combo that is sometimes a little tough to put together these days.....proper chambering and a correctly made reamer.

Untwist thy knickers, Joe. Why the dissertation? All I asked was how long does removing machining marks take you by hand with JB on a patch.
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I always read and was told that JB Bore Cleaner {the muddy gray looking stuff} was non-abrasive/non-imbedding.....the active ingredient is chalk. I didn't know it could be used to take out machine tool marks. JB Bore Bright is a polish {abrasive}, but an extremely very fine one....works good on the sides of a Rolex case.
I guess whatever gets you thru the night.......

Edit: you know...thinking about it, how many people would buy JB if they had it written right on the can that it was abrasive to the point it would take out tooling marks???? "Removes copper" does have a less destructive sound to it.

 

[JRS]

That can be a combo that is sometimes a little tough to put together these days.....proper chambering and a correctly made reamer.



I always read and was told that JB Bore Cleaner {the muddy gray looking stuff} was non-abrasive/non-imbedding.....the active ingredient is chalk. I didn't know it could be used to take out machine tool marks. JB Bore Bright is a polish {abrasive}, but an extremely very fine one....works good on the sides of a Rolex case.
I guess whatever gets you thru the night.......

Toothpaste also works quite well, and has for many decades

 

[Joe Salt]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

JRS give me a break, they all leave burrs. No such thing as perfect.

Joe Salt

 

[6MMsteve]

I use Diamond suspension 1.0 apu then polish with JB

 

[JRS]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

JRS give me a break, they all leave burrs. No such thing as perfect.

Joe Salt

I've got news for you, Joe. The rifle smith I trust to build my guns demand's and exhibits perfection. Perhaps you might consider contacting him

 

[RustyMetal]

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[ridgeway]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

I agree with Joe...anytime you cut metal...you WILL have tool marks and a small burr.

 

[Joe Salt]

JRS you must be using my guy, because he is the best! And I still do a little polishing.

Joe Salt

 

[swd]

Toothpaste also works quite well, and has for many decades

And smell minty fresh

 

[SBS]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

JRS give me a break, they all leave burrs. No such thing as perfect.

Joe Salt

Yep, if you use a mechanical cutting tool, it will leave a burr at the end of the cut. It cuts by means of shearing the metal and therefore at the end of the cut has nothing to shear against. You can take the sharpest and best made drill and drill a hole through any type of steel and there Will be a burr at the end of the cut. When cutting a chamber, the reamer is primarily cutting crosswise of the rifling. The area from no rifling to full rifling will have a small burr at the end of each land cut when finished reaming. A good borescope will confirm this. Joe has the right idea to smooth out the burrs' edges. It doesn't remove the tool marks, but it does reduce the tendency to copper foul. Much more important on rimfire chambers, which take much longer to smooth out by simply shooting, as lead is much softer than copper.

 

[msinc]

I have a Hawkeye borescope...I was just wondering if that is a good one????? because if it is I am not seeing all these burrs either. I run the rpm's up as I finish and I feed very slowly. I have yet to have to rub out any burrs in the barrels I chamber.
I learned this from cutting muzzle crowns...spin fast, feed slow and you wont have to lap the burr off the muzzle. I don't believe it's necessarily accurate or "fair" to compare finish reaming a chamber to drilling a hole thru steel. The chamber reamer is not all of a sudden busting thru anything all at once and it does not require that you apply much pressure to do it's job. You can ream as slow and with as little pressure as you want, slow down a twist drill and/or ease up on the pressure and it stops cutting and just rubs.
Not that your theory is wrong or even flawed...look at a barrel contoured by some makers and then have a look or even better yet put the final finish on a Schneider barrel and I am sure everyone would agree with what you are saying. It's like "dude, did you break that tool bit three or was it four years ago?????" Or "is your contour lathe stuck in high feed gear and you didn't notice it ran out of coolant?????"

 

[Raythemanroe]

If your barrel has been properly chambered with a sharp correctly made reamer, you won't have to do that

JRS give me a break, they all leave burrs. No such thing as perfect.

Joe Salt

I put him on ignore and things have been much more civil ever since.. It worked great

Ray

 

[ridgeway]

I have a Hawkeye borescope...I was just wondering if that is a good one????? because if it is I am not seeing all these burrs either. I run the rpm's up as I finish and I feed very slowly. I have yet to have to rub out any burrs in the barrels I chamber.
I learned this from cutting muzzle crowns...spin fast, feed slow and you wont have to lap the burr off the muzzle. I don't believe it's necessarily accurate or "fair" to compare finish reaming a chamber to drilling a hole thru steel. The chamber reamer is not all of a sudden busting thru anything all at once and it does not require that you apply much pressure to do it's job. You can ream as slow and with as little pressure as you want, slow down a twist drill and/or ease up on the pressure and it stops cutting and just rubs.
Not that your theory is wrong or even flawed...look at a barrel contoured by some makers and then have a look or even better yet put the final finish on a Schneider barrel and I am sure everyone would agree with what you are saying. It's like "dude, did you break that tool bit three or was it four years ago?????" Or "is your contour lathe stuck in high feed gear and you didn't notice it ran out of coolant?????"

It happens right at the lands. The tool marks are perpendicular and the burr or wire edge is left on one side. Probably hard to see the burr/wire edge if looking 90 degrees to it via borescope. Sharp, fine ground reamers leave a better finish and less of a burr/wire edge. The burr/wire edge would be less pronounced on lets say a 5R vs conventional rifled barrel due to rifling design. Regardless of what anyone tells you...there WILL be tool marks and or burr/wire edge left behind at the throat. Its the pure nature of machining and reaming a chamber. Iosso the heck out of the throat will polish most of it away after machining.

 

[gunsandgunsmithing]

Boy these borescopes sure have changed the game..at least with respect to what the masses now see. I'm a believer in proper break in but one has to realize that the burr we're talking about is very tiny. The entire land is only about as tall as a human hair is thick..about .004"

Not saying there isn't a burr or that you shouldn't do a proper break in..just putting things in perspective.

And FWIW, these precious and delicate barrels are lapped to pristine finish with between 240-320 grit abrasive. Sure wouldn't want to put a bronze brush in there, but that's another subject.