Fly: The Best "education" you can get about reading patches, and targets to learn what is going on inside the barrel of your MLer can be found in Dutch Schoultz' Black Powder Rifle Accuracy System.
Go to this site:
http://www.blackpowderrifleaccuracy.com/
and order Dutch's system. Its the cheapest $20.00 you are ever going to spend.
To answer your question, a spent patch, that was properly lubed, should show NO holes in the center portions of the fabric.
The Edges will FRAY when they are Whipped back at the muzzle when the fabric hits the air. But the fraying generally is about 1/32-1/16" back from the edge, and should go no further.
The very center of the patch should be discolored- yellow to orange from the lube burning at the back of the patch. It should not be BC, or be burned away!
There should be a darker- brown to black-- soot RING where the edge of the RB actually pushes against the patch and barrel. Typically, this should be a ring about 1/32" wide, but a complete circle. The Edges of the ring should be well defined.
If you have tears in the patch, either the patch is too thin for the Ball and bore diameter combination, or you are not using the right lube, or enough lube.
If you get holes in one spot consistently, look for a sharp edge on the face of the lands at the muzzle Crown. If not that, then you have a burr or sharp edge on one( or more) land(s), that needs to be removed.
If you see little black soot "daggers" going forward of the RING of soot on the patch, the patch is not providing a good enough seal in the bottom of the grooves. Either use a thicker patch, or consider using an OP wad or Filler between the powder and PRB. OP wads and fillers provide a better gas seal, and a "FIREWALL" that protects a thin patch from burning.
You can't change anything without knowing to the thousandths of an inch, what your bore and groove diameters are, and then what your ball diameters ARE. Do not trust the stampings on commercially- boxed, Swaged lead balls. They may or may not be the diameter indicated on the box. If you don't have them, investing in a good caliper, and a good micrometer is a life-time investment that will prove useful in many ways. I recommend a DIAL caliper, rather than the new Digital Caliper for anyone who is not employed as a machinist, as you simply don't use calipers enough as a hobbyist to justify the greater cost of the digital calipers, and they become just another place to store dead batteries! :shocked2:
You can buy a good dial caliper for less than $30.00 from a number of suppliers listed here on our "Links" pages, as well as from Harbor Freight. Because of the advent of digital micrometers, a lot of very fine quality micrometers that were hand turned and read to 1/10,000 th of an inch are available used for very good prices, if you haunt tool auctions and sales. I see them at flea markets, too. A Click-adjusted micrometer should be available for about $75-$100.
Understand that casting bullets from wheel weights, or any alloy of lead containing tin and antimony will produce LIGHTER weight balls, and balls that are slightly LARGER in diameter, than balls cast from pure lead. The Antimony will make the balls Harder, so they don't expand on impacting flesh like a pure lead ball does.
Hard alloy lead balls are often CHOSEN by hunters when they want greater penetration when hunting dangerous game. Adjustments in patch diameter, and lube choices are made to match these harder balls to their particular rifle. :hmm:
But, reading your spent patches is the key to understand what change is needed. :shocked2: :thumbsup:
