What do the patches look like after they are fired? .010" patching is pretty darn thin stuff. I would suggest you use .490" balls, and .015-.018" thick patching, with a good lube. If you like the lubes wet, then by all means use Hoppe's #9 Black Solvent and Cleaning solution. If you want your lube thicker, use bore butter, wonderlube NL1000, or any of its incarnations.
Then, again, I happen to think highly of Stumpy's Moose Juice, and Moose Snot, the formulas being available to you at the Top of the Index page to this forum, under Member Resources. So, you have a choice of making your own, or buying something commercially.
I don't know what you are doing to clean the barrel between shots, but you should be using a good cotton flannel or pocket drill patch, with a good cleaning solvent. Even water, and spit, are better alternatives. If you are shooting in a humid part of the country, run a Damp- not dripping wet- patch down the barrel, stopping an inch short of the breechplug. Then pull the patch out. If its really filthy, and greasy black, GOOD! Its doing its job.
Now, if the other side is useable, flip it over and run it down to the breechplug to pull out any gunk collecting on the face of the plug. If you have a reduced diameter powder chamber, you need to use a separate, smaller diameter swab, or jag with a patch to clean out the powder chamber.
If the other side of that first patch is not useable, then use a second damp patch to do these final tasks. Then run a dry patch down the barrel to dry it out. In the wintertime this generally will not be necessary. Nor is it necessary in very dry conditions, as evaporation will dry the warm barrel quickly. Pay attention to the relative humidity of the air on the days you shoot, and modify your cleaning procedure accordingly. Don't ever be afraid to use an extra cleaning patch down that barrel.
Oh, flipping that first, dirty patch over, and running it down the barrel is a quick way to get the cleaning rod dirty. Wipe it off to save yourself from looking like PigPen at the end of the day. Always take towels, and some soap and water to clean your hands, and maybe your face, and then the outside of the rifle after a long day at the range. It won't make that gun shoot any better, but it will make you feel a lot better about shooting it.
To get small groups, you have to be consistent in how you load each load. Cleaning between shots allows the gun to be shot in the same condition each time its fired. Sometimes, people will dump the first shot, just to dirty the barrel, before shooting for groups. Test your gun both ways, and do what it takes.
Mark your Ramrod when you find a load you like. Always load to the mark, as it will tell you if you are cleaning the barrel properly. I suspect that since its the 3rd shot that is flying off, you are not cleaning the barrel adequately. When crud builds, you won't be able to seat the ball in the same place until you get the crud out of that barrel! And the crud is building in the grooves because you are using too thin a patch, that does not fill the grooves.
My .50 Cal. Rifle has a 39 inch barrel. It likes a load of 60 grains of FFg, or 55 grains of FFFg powder for target work, out to 50 yards. I use the .490 balls, and the .015" patches, with wonderlube. In the Wintertime, I clean with Alcohol, when its below 32 degrees out. I still use Wonderlube, but keep the can with my pre-lubed( by me that morning) patches in an inside pocket so that my body heat keeps the patches flexible.
I hope this helps you. I learned all this from a very kind, older member of my gun club who took me under his wing, and showed me what to look for, and told me how to clean my gun. My shooting improved immensely. I have since helped many other new shooters deal with similar problems, and they are always amazed that us " old guys" can simply listen to them describe the problem, and have a pretty good idea what they are doing wrong. If you have access to a black powder club, with some experienced shooters, ask them to critique your loading and firing techniques. Ask them for suggestions. Watch them load and fire, and clean their guns. You will find out quickly who are the better shooters by the holes in THEIR targets. Those are the guys to immitate.
