In my almost 40 years of shooting Muzzies, I have only seen three things that foul a barrel so bad a second shot is hard to load without wiping: A rusty bore, a pitted bore, and rough-cut grooves with chatter marks. All three tend to hold on to fouling. The only thing I’ve seen a new barrel do is cut patches, both shooting and cleaning. I’m in a quandary.
I know Wheeler makes a Lapping kit with three grits: 220, 320 & 600. I just bought one for another project. In the meantime, a kid in our club shot his guns and unbeknown to us, didn’t clean them until right before the next match. He was plagued with misfires and hard-to-load problems. A bore light proved them to be rusted. One member volunteered to lap the bores with Valve Grinding Compound. I’m told there are different grits, but most stores only carry one made by Permatex. I wasn’t totally happy with the results, so I used J-B Bore Cleaning Compound which I thought might be finer than the Permatex. Next, I used toothpaste and followed up with 0000 Steel Wool. Each step was 100 strokes. I used water on the patches with the Bore Cleaner and toothpaste. I used Hoppe’s #9 for the steel wool. The patch material was taken from an old pair of jeans and held up very well. The bores look brand new.
Now let’s talk about patch/ball combos. My experience with a thin patch (.010) is they won’t hold up to a heavy powder charge without some sort of wad or backup patch. I like a tight combo. In rifles with deep grooves, oversized balls (.445, .595, .535, etc.), and thick patches. My preference is Pillow Ticking which is usually .017 to .018. It’s Sturdy and has a nice solid weave which acts as a great gas seal.
According to Dixie’s catalog, the Lyman (Investarm) GPR has 5 Lands and Grooves and .010 deep “Cut” rifling. That means it should be able to handle a thick patch.
I know I haven’t really answered your question so far. Here’s my suggestion. Since you have done the research and found a video with the same problem on the same model gun, I’d try the Scotch Brite method. You can purchase them at the Dollar Store. I’ve done this before and they’re thick. I started with a smaller jag, then moved to a bigger one, then bigger again. When I did a 50-cal, I used something like a 40-cal jag, then a 45, and then the 50. It flattens out a bit at a time. I’ve put them on a 50-cal jag and punched through the center just trying to get it in the muzzle. So, I do it in steps. Mike makes it seem much easier on his video!
Part of the fun in this sport is experimentation. It can be frustrating at times. Like when I’m sighting in a new ML at 13 yards and get fantastic groups, bench rested. Then move it out to 25 and they’re all over the place and all I changed was the distance!
Wishing you much success!
Walt
I know Wheeler makes a Lapping kit with three grits: 220, 320 & 600. I just bought one for another project. In the meantime, a kid in our club shot his guns and unbeknown to us, didn’t clean them until right before the next match. He was plagued with misfires and hard-to-load problems. A bore light proved them to be rusted. One member volunteered to lap the bores with Valve Grinding Compound. I’m told there are different grits, but most stores only carry one made by Permatex. I wasn’t totally happy with the results, so I used J-B Bore Cleaning Compound which I thought might be finer than the Permatex. Next, I used toothpaste and followed up with 0000 Steel Wool. Each step was 100 strokes. I used water on the patches with the Bore Cleaner and toothpaste. I used Hoppe’s #9 for the steel wool. The patch material was taken from an old pair of jeans and held up very well. The bores look brand new.
Now let’s talk about patch/ball combos. My experience with a thin patch (.010) is they won’t hold up to a heavy powder charge without some sort of wad or backup patch. I like a tight combo. In rifles with deep grooves, oversized balls (.445, .595, .535, etc.), and thick patches. My preference is Pillow Ticking which is usually .017 to .018. It’s Sturdy and has a nice solid weave which acts as a great gas seal.
According to Dixie’s catalog, the Lyman (Investarm) GPR has 5 Lands and Grooves and .010 deep “Cut” rifling. That means it should be able to handle a thick patch.
I know I haven’t really answered your question so far. Here’s my suggestion. Since you have done the research and found a video with the same problem on the same model gun, I’d try the Scotch Brite method. You can purchase them at the Dollar Store. I’ve done this before and they’re thick. I started with a smaller jag, then moved to a bigger one, then bigger again. When I did a 50-cal, I used something like a 40-cal jag, then a 45, and then the 50. It flattens out a bit at a time. I’ve put them on a 50-cal jag and punched through the center just trying to get it in the muzzle. So, I do it in steps. Mike makes it seem much easier on his video!
Part of the fun in this sport is experimentation. It can be frustrating at times. Like when I’m sighting in a new ML at 13 yards and get fantastic groups, bench rested. Then move it out to 25 and they’re all over the place and all I changed was the distance!
Wishing you much success!
Walt
That was a total of 300 strokes that night. Thank God it was a short-barreled gun! I needed to have them done by this weekend otherwise I would have spaced it out more.
