Well I have about 75 rounds through the Lyman GPR and I still cannot load more than one round without swabbing the bore with some solvent . I thought by now I would be seeing some improvement. I watched the polishing video with Scotch Brite pads and that seemed easy enough . However I didn't have any but I did have some JB bore paste. I did 50 strokes with double patches and a good coating of JB . It looks shiny when I point a light down the bore . It will be a couple of weeks before I can give it a try. I tried to search lapping with JB but I didn't find a definitive description and results . I will update when I have results in a week or two.
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Lapping the Barrel with JB bore Paste
- Thread starter jambuster
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valve lapping compound
What are you lubing your patch with? How thick is your patch. If it’s not cutting the patches then it’s fine. You need a wetter slicker lube or a thinner patch. Try your patch with some spit or use a thinner patch. Use that solvent your cleaning with as a patch lube.
I have a 54 cal gun. I am using .530 Hornaday balls and I have tried .015" and .018" patches with the same results. I am using mink oil to lubricate the patches and they are thoroughly wetted out. The gun is very accurate. Also the patches look fine when I recover them.
JB may be too fine, depending on how rough the bore actually is. 320 grit Clover compound is good as is fine valve grinding compound. If the bore shows reamer marks across the rifling that may be the problem. If it's smooth then it's something else wrong, like the lube. As mentioned, check the patches for being cut.
Try using a wet patch lube like Hoppe's No. Black Powder Gun Bore Cleaner (formerly called No.9 Plus) or Mr. Flintlock's. Using one of these as a patch lube in effect swabs the bore when you seat the ball. As wet lubes they aren't as suited for hunting but for target shooting they are great and should allow you to keep shooting without swabbing.
64Springer
75 Cal.
Unmen shooters roll their bullets in fine abrasive to fire lap/smooth out a bore.
What would happen if patches were lubricated with finer and finer lapping compound?
What would happen if patches were lubricated with finer and finer lapping compound?
It would get smoother and shinier! I have 'fire lapped' many a rifle or pistol!
I myself would NEVER use any valve grinding compound as there is a major difference between gringing and polishing. I do use the 2 grades of J&B Bore Paste on any of my 'toys' that may need it, putting it on a grey ScotchBrite if needed to do what the OP wants to do. I also have a supply of 5 different grits of lapping compounds.
I’ve built three Great Plains kits in the last five years. One 50 cal and two 54 cal. Never not once did I have an issue with loading a 530 ball and an 18 patch. I use windshield washer fluid in a squirt bottle for lube or spit. All of them went down smooth as butter without wiping between shots. I have another dozen muzzleloaders and I’ve never had to lap a barrel. On the other hand I shoot for accuracy and I use a small brass hammer and short starter to start the ball. Once short started the ball goes down easily. So I like a tight fit. For hunting I use mink oil and a thinner patch for easier loading. Wetter patch and continue shooting. It’ll break in. On the other hand if it shoots good then just wipe between shots. Many people do.
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TDM
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Unless I missed it, what is your caliber and what are you trying to load it with?
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JB bore paste is for removing copper and lead fouling, not polishing steel. You need something like a valve lapping compound of very fine grit to polish steel. NAPA has what you need.
Uncle Miltie
50 Cal.
Lapping a bore won't reduce the amount of fouling.
I should also mention I am using Graff fffg powder CCI and Rem 11 caps. Duelist54 in his video suggests that it is micro-burs causing the problem. My gun is acting just like his. I figured I couldn't hurt anything with the JB so it was worth a try. If that doesn't work I'm going to give it the scotch bright testament. Also ,until i shoot it again i have the shinnyest bore in town.This gun is very accurate and if I could load two rounds with no problems I would not care. However, hunting I need to have the option to reload. Also it's just great to hear from fellow enthusiasts in this sport.
Thanks guys !!!!
Thanks guys !!!!
It may not reduce it (the amount generated as a by-product of combustion) ... but it sure will leave or deposit less of it in the barrel! That's for darn sure!
Find a different lube, it's the fouling that's causing you the problem not the bore.
There's got to be 57 different brands of "Mink Oil" on the market,, the stuff your using is obviously reacting with the powder residue in a manner that's creating excessive fouling.
Even if your accuracy falls off a bit with a different lube,, those issues can be fixed with minor changes to the charge if needed.
A 54 will easily take deer size game with loads as small as 60grns,,
FWIW, all I've ever used to lap a new bore is Auto grade polishing compound and only 100 strokes.
And in my experience "very accurate" with a new barrel doesn't begin to show up until you have about 200 rounds through it, it takes that much just to find the right combination of patch thickness, lube and charge. You have to approach each of those variables with experimentation.
The lube is causing your problem.(period)
There's got to be 57 different brands of "Mink Oil" on the market,, the stuff your using is obviously reacting with the powder residue in a manner that's creating excessive fouling.
Even if your accuracy falls off a bit with a different lube,, those issues can be fixed with minor changes to the charge if needed.
A 54 will easily take deer size game with loads as small as 60grns,,
FWIW, all I've ever used to lap a new bore is Auto grade polishing compound and only 100 strokes.
And in my experience "very accurate" with a new barrel doesn't begin to show up until you have about 200 rounds through it, it takes that much just to find the right combination of patch thickness, lube and charge. You have to approach each of those variables with experimentation.
The lube is causing your problem.(period)
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TDM
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smoothshooter
50 Cal.
JB’s is not nearly aggressive enough.
The Mink Oil I am using is from TOW so it should be fine for my needs
My 90's era .54 GPR sliced patches into ribbons when new with any kind of patch on a .530 ball. After a good scrubbing with scotchbrite on a sub caliber jag and 50 rounds or so, it loads easy and does not cut patches.
Some bores are cutters and you just have to slick them up a bit.
Some bores are cutters and you just have to slick them up a bit.
You could try a different powder, if you have any available. I've not used Graf's, but at a recent shoot one guy was using Graf's for the first time and was very unhappy with the fouling compared to GOEX (which he couldn't get and had bought Graf's). He was unable to load more than 3 without swabbing.
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