Tubb bore polishing system

JB, being non embedded, cant cut barrel steel. It won't do a thing to machine or tool chatter marks, right ? Can anyone recommend a hand lapping (not fire lap) product that can be used carefully by a rookie ? That's a loaded question I know. Thanks.

"Don't try to fix what's not broke" Keep hearing this little voice in my head.......
 
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That's right. JB Bore Paste will have no effect on removing tool marks. A "rookie" is far better off firelapping than trying to lap a barrel with a lead slug. It sounds to me like the Tubb Bore Polishing Kit might be a good idea. Just go easy, and don't over-do it. I suggest using (or borrowing) a bore scope on your first barrel or two.
 
Fire lapping a barrel with lead bullets is very effective. I have done this on a factory barrel. It is neccessary to have a very
clean barrel to begin with. I did this as an experiment and monitored it with a borescope and fully cleaned between each
shot. Loads were reduced and I used clover compounds rolled into the bullets. It did a great job in the grooves but there were
very stubborn tool marks on the lands so I tried copper jacketed bullets using a very fine grit and advanced the throat quite
a ways. Hand lapping an installed barrel presents a whole new problem, that is introducing the lapping compound without
developing some belling. Unless you plan on shortening the barrel afterwards, I don't see how this can be done.
 
JB can be used to smooth up actions .
In this application metal is removed.

I could see damage happening if the rod isn't straight or no bore guide used.

Be carefull .

Think.

Glenn
 
NON EMBEDDING does not mean it cant cut steel. ive been lapping steel parts with non embedding compound for a lot of years, and the steel always loses!
 
Even water can cut steel if you go to rediculous extremes. Try scrubbing a smooth piece of steel with JB Bore Paste, and see what happens. It would take a jillion years to affect steel to any measurable (or detectable) amount. The steel will become perfectly clean . . . . that's it.
 
I used to use it to clean the gunk off disk brake parts. It was great stripping off the oil & seal residues & leaving the cylinder squeaky clean.
 
ive seen 1911 slides and frames lapped in with JB, and it does remove steel. this is why i ask questions, because with my own eyes ive seen it do what everybody claims it cant.
 
Hand lapping an "installed" barrel works quite good if it is done correct.
1. Lap from the chamber end.
2. Use a fitted bore guide. The barrel saver or similar guide is needed. Without a premium bore guide you will damage the bore.
3. Use the correct lapping compounds. Brownells Silicon Carbide Abrasive Kit PN 080-905-000 or equal. Use the correct grit. The kit comes with 120 to 800. Most of the time I use the 400 grit first, then 600, then 800 and then the JB.
4. The exact technique varies barrel to barrel. Soft lead slugs are the best but I often use patches on "Parker" type jags. Usually 25 stokes per grit. Detail clean between grits.
5. A barrel lapped with the correct procedure and materials will not have any belling. There will be a very slight taper with the choke to the muzzle. Near impossible to measure.
6. Generally the hammer forged barrels are the most difficult to lap as they tend to need it the most. One of the recent hammer forged barrels we did was a Ruger 308 Model 77. Before it was shooting best groups at over 2". Now it shoots under 1/2" and some times less. This was an exceptional improvement.

Hand lapping is not easy and it does take a lot of work. To get the best results you must do it right and use the correct materials. Done correct hand lapping does not erode the chamber end. I have never seen fire lapping give equal results. Fire lapping is fast and easy and it does improve some barrels, especially if the barrel is quite bad.
 
Wilbur said:
Glass and steel ain't the same (profound) but Jay Johnson did a test on glass with 3 common "abrasive" bore cleaners. ......... the JB sample glass was unbelievably unaffected. The most affected sample was RemClean or whatever they call it. The glass was burnished such that it was opaque but Jay said that the "damage" was not measurable using a fancy measuring device.
Click to expand...

Your first comment says it all. Glass is much harder than steel. Whatever affects glass will affect steel, but it is completely incorrect to conclude that what does not affect glass will not affect steel.

Cheers!
 
I used the Tubb kit on my Savage in .223 and had mixed results.

I used the whole kit. First, because the instructions said to, and second, because I have a borescope and saw the exact same tooling pattern in my barrel. Ugly to say the least. Little did I know at the time, the appearance of the bore in this barrel had no effect on how well it performed on the target.

After I used the kit, I inspected the bore and it appeared much better. It now was smooth and shiny all the way through. It also cleaned up much easier than it did before the treatment.

Now for the bad part. The lands moved .140!!!!!!!! This made it so that the only bullets that could get near the lands was the 69gr Sierra. Fortunately it likes those bullets, but a whole new load workup had to be done. Even after all that, it shot no better, just cleaned easier.

My advice would be to shoot the barrel as is, and save up for a good barrel from Savage Shooters Supply. I have one in 30BR and it's killer! The Savage factory barrels in chromoly steel are about the same hardness as hot rolled steel. It's not like you are dealing with a bar of 4140 or something anywhere near it.

As to the thoughts on JB, burnishing steel is not nearly the same thing as removing it. The particles are too dull to remove steel. Round bearings and ceramic balls are used to burnish steel all the time. If it removed material and changed the dimensions of it, they would use something else!
 
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