JB Bore Paste Question

I've done searches for comments on the paste but all are rifle applications.  Do any of you pistolsmiths know if the product is useful and, if so, what criteria would you use before running a few patches through the bore?  Thanks.

It works well for its intended use. 

For cleaning No! If the barrel is very old or excessively leaded, Copper fouled or pitted it might bring some life back. 

For minor leading and cleaning, if Hoppes #9 does not cut it try Hoppes Bore Gel, I think it works well and I am unaware of any problems with Bore Gel.  

http://shop.brownells.com/gun-cleaning-chemicals/solvents-degreasers/bore-solvents/hoppe-s-elite-bore-gel-sku699000016-25972-45819.aspx?cm_mmc=PPC-_-Itwine-_-Google-_-699-000-016&gclid=CLiCqrLbhswCFckehgoduPoLUQ

It is an abrasive so it should be used seldom and cautiously. I have used it on rifle barrels but I have reduced the frequency of use. I talked to Frank at Compass Lake Engineering over this, over time the throat in a rifle barrel will copper foul. Sometimes gunk imbeds. Either or the combination will ruin on target accuracy.  If copper solvents won’t restore accuracy then the imbedded gunk has to be mechanically removed. Frank has had barrels sent to him that were not grouping, cleaned them with JB, and the barrels shot well again. Frank also has a bore scope and can examine the interior of a barrel.
 
For a pistol, I would not use the stuff unless you had severe leading or copper fouling that a bristle brush and soaking with solvents won't remove.  Because the stuff is an abrasive I am of the opinion that it will remove barrel steel as well as the gunk, so, be cautious.

I have both factory/stock barrels for pistol, rifle and shotgun along with some very high end match barrels and I would never use an abrasive like JB Bore. If regular cleaning techniques are not working it may be time for barrel expert to look at it vs. trying to rub or polish it without the full knowledge and tools to do it right.

Since no pistolsmiths have responded, I'll add my experience. JB Bore Paste is safe for use in barrels and some manufacturers recommend it when breaking in a barrel. I used it in my Rock River National Match AR-15 when breaking in the barrel and had very positive results. It won't hurt to use it in a pistol barrel. It doesn't take much (just a little dab smeared on a patch). After you use it, make sure that you get all of it out (I use Kroil). I would never use JB regularly in a barrel, but it might be useful in a new barrel or one that has been neglected over the years. I always clean the barrel as thoroughly as I can by traditional means before using JB.

Thanks all for your comments and suggestions.  I did receive my order of JB, can of Kroil and 3 nylon bore brushes yesterday.   Today I recleaned my RO9 bore by running a swab patch of Kroil down the barrel followed by nylon brushing and followed with dry patches on a jag.  The residue came out a dark brown and I repeated the process until the dry patch just showed a very light gray/brown after about 10 passes.  This was done after my normal cleaning on Saturday with #9 solvent, bronze brush and patches.  So the Kroil, although not a solvent, does loosen something the #9 doesn't touch. 

I was thinking I must have some copper fouling after over 2000 rounds but whatever residue that was, wasn't copper and the bore never saw lead.   Since I saw no evidence of copper fouling I'll hold the JB aside until such time as it's needed.   I most likely will use it on my Sprg 03-A3 deer rifle I've had since '65 as the seasonal cleaning has shown blue and green on the dry patches the last few years.  Thanks again gentlemen.

Kroil is pretty amazing stuff. Not only will it get under fouling in a barrel, I've used it for other applications. I used it on an old beer stein with a music box in the base. After many years of not being used, it had frozen. A couple drops of Kroil and it started playing again. I also used it to lubricate an old anniversary clock. The pendulum had quit turning long ago. After letting a couple of drops of Kroil soak in, the pendulum started turning and has been running fine for many months.

mix it 50/50 with Hoppe's and you have a great solvent

If you use the JB or something like Montana Copper Cream, I bet that the patches will come out black. I've seen this happen with "clean" rifle barrels before. 

JB also works well if you accidentally fire some corrosive ammo that should not be corrosive. 

Kroil certainly has solvent properties due to its penetrating effects. It breaks up wax build up better in a 22 than anything I have ever used. The BR50 guys (who I learned about it from) mix it 1:1 with shooters choice. I use it straight and then follow it up with Hoppes #9 or CLP, followed by dry patches.

BE Mike wrote:Kroil is pretty amazing stuff. Not only will it get under fowling in a barrel, I've used it for other applications. I used it on an old beer stein with a music box in the base. After many years of not being used, it had frozen. A couple drops of Kroil and it started playing again. I also used it to lubricate an old anniversary clock. The pendulum had quit turning long ago. After letting a couple of drops of Kroil soak in, the pendulum started turning and has been running fine for many months.

Hot Damn ! 

After reading this, I put a little Kroil on the pendulum of an anniversary clock that also hasn't moved in well over a year - it's fine now. Thank you !

My two cents on JB is that it worked very well for me to get heavy copper fouling out of a couple of slightly rough rifle barrels, which I then fire lapped after cleaning, which cut the group size tremendously. I also use it as a small parts lapping compound. I think I read somewhere that it will remove .0003" of metal from a barrel. Used very occasionally on a bore, I don't think it will do any harm. 

Walt

i use JB in one ocassion for clean my 52-2 barrel with hoppes oil and after clean the barrel with outers solvent; next time i buy kroil.

Well, I have been searching .. I went back thru decades of Precision Shooting magazines looking for an article describing the JB mixture..I remember reading it, I just can't find it..  I'll subject  my memory to flames here, but as I faintly recall, the early JB was a pulverized clay compound .. Later compounds use a pulverized plastic, which does not harm the bore..I can find no evidence that the clay harmed the bore..
I use JB, and use it often..I have a five gallon can of Kroil, that's how much I like it.. I have several jars of JB sitting around.. I have never detected any negative effects.. I use a bore scope regularly.. I can see no effect from its use other than stripping residue from the bore. I am adamantly against lapping  bores.. The bore will never be better than the day it arrives from the maker..

+1 on Kroil, a buddy that's into Model T Fords turned me onto it 35 years ago.  Since then I have had several cans & aerosols around the shop(s).  I've never encountered a rusted bolt that couldn't be loosen after spraying it down with Kroil.  

Nothing better at cleaning barrel fouling.  I drop or spray some in the barrel and let soak, usually 1 or 2 passes with a brush or patch will clean it up. 

I've only used JB a couple of times (on rifles) but based on Jerry's experience I won't be shy of using it if I think it's needed.

- Dave

Back in the 90's I bought match rifle barrels from Boots Obermeyer. Along with a new barrel he would include a bottle of Gold Medallion. This mechanical cleaner later became Rem Clean. It works on the same principal as JB compound.

Boots worried about shooters using Sweets and the like in his stainless barrels. I used mechanical cleaners including JB and never did any damage to his fine barrels. He once told me that the most harmful thing you'll do to a barrel is fire a bullet through it.

Jim

dang I thought I was bad buying Kroil in Gallon cans....

always used JB on my rifles. works very well on fouling

see no reason to be afraid of it on pistol bores..

I have used Kroil.  It is very good.  But I have a Milspec penetrating oil from an ink mfg. that cleans to the bone even better.  I can't remember the name of the stuff.  It is pre-MSDS era.  Nasty too.  Stinks, and gives a bad taste in your mouth.  You better use it outside and wear protection.  This badboy oil works better and quicker that JB.

ink mfg? probably 1,1,1-trichloroethane

james r chapman wrote:ink mfg? probably 1,1,1-trichloroethane

Hmmmm. Have I ever used a bunch of that.. We maintained a stock of numerous 55 gallon drums of Trichlor..and used it like water..