I copied this from North American Hunting Clubs website. Most of the things that is mentioned is exactly what I do.
Basics For Better Groups
For the best accuracy, you should swab the barrel after each shot when sighting-in at the range. Swabbing can be done with pre-soaked patches from the factory or "spit patches," whereby you chew on a patch until it soaks with saliva. Swabbing the barrel with a damp patch removes ignition residue and prevents build-up in the bore that results in difficult bullet loading and poor accuracy. I believe the tiny amount of moisture left in the bore after swabbing also makes it easier to seat the bullet.
Swabbing is a simple job, but I regularly see shooters doing it wrong. Don't push the rod to the bottom of the barrel in one stroke. Doing so piles up residue on the patch, and as this accumulation increases the patch gets tighter in the barrel, to the point the ramrod is almost impossible to pull back out. Instead, push the barely moist-to-the-touch patch down the bore in 4- to 5-inch jabs. These short jabs prevent the ramrod from getting stuck in the barrel.
Always discard the first moistened patch after removing it from the bore. Next, you can swab a second time with a moist patch or simply run a dry patch down the bore. I've found that one slightly moistened patch followed by a dry patch results in excellent ease of loading and accuracy.
I prefer commercial patches because they're cut for the bore-size of your muzzleloader. Many shooters prefer to cut their own, using cheap flannel or similar material. I haven't found any significant advantages between patch material, size or shape as long as the patch fits snugly in the bore. T/C and Knight offer round patches that work great, and I've also used 2-inch-square patches with fine results.
I use T/C pre-lubed patches for the damp patch with one warning: To ensure the patches stay moist, T/C places a surplus amount of solvent in each container, and I suggest you remove five or six patches and squeeze the juice out of them before use. Having the patches just moist to the touch is best. I also make my own moist patches by placing a bunch of them into a plastic container with a tight-fitting lid, then pouring T/C's Number 13 solvent over the patches and letting them sit for a while so the solvent is fully absorbed.
If you shoot a lot, consider buying a range rod for swabbing the barrel and seating bullets. Heavy-duty one-piece range rods are longer than the rod supplied with your gun, and they have a comfortable handle that makes pushing and pulling easier.
Always exert the same amount of pressure when seating the bullet on the propellant charge. I like to give the rod a smart tap when I get to the bottom of the stroke, regardless of whether I'm using loose powder or pellets. An important reminder if you're using powder in pellet form: You don't want to crush the pellets with too much force as this will result in uneven ignition and marginal accuracy.
When my friends and I have a new in-line muzzleloader to sight-in, we like to experiment with a variety of propellants and projectiles. Although pellets are by far the most user-friendly, some in-lines don't shoot as accurately with pellets as they do with loose powder. I start my accuracy test with Triple Seven pellets and then try Pyrodex Pellets, too. Then, if I'm not happy with the accuracy, I'll switch to Triple Seven and Pyrodex loose powder.
I always start with two 50-grain pellets (measured by volume) and a 250-grain bullet (measured by weight). Then I'll try three 50-grain pellets to let the rifle determine the combination it prefers. Shooter's tip: The best accuracy is usually achieved with bullets and sabots of the same brand as that of your in-line muzzleloader. That means T/C bullets typically shoot best in T/C in-lines, Knight bullets in Knight rifles and the same for CVA and Traditions.
Primers are a non-issue in my opinion. I haven't found any accuracy improvement with the new primers designed specifically for muzzleloaders, and as a matter of fact I prefer to send as much flame into my propellant as possibleâ€”we're trying to set-off a detonation here, not start a progressive burn. When my rifle is cold, maybe sweating or whatever, I prefer as much fire as I can get to ignite the charge. I don't buy into the claim that too much flame can push the powder charge forward because I've seen far too many sub 1-inch groups shot with three pellets and standard primers. But if you believe the new primers work well for you, then go to it.
Some shooters are surprised to learn that many popular saboted muzzleloader projectiles are actually handgun bullets. Velocity loss frequently ranges as high as one-third in the first 100 yards of travel according to my chronographs, and terminal performance isn't much better. (I once said that most muzzleloader bullets have the ballistic efficiency of flying trash cans.) And even at low impact velocities, these handgun bullet cores and jackets frequently separate.
Thankfully, today's shooter has aerodynamically shaped bullets specifically designed for muzzleloaders, and they feature relatively sharp tips that retain velocity and energy better. I've tested the new T/C ShockWave, Hornady's SST and the Spit-Fire MZ from Barnes and found that these bullets retain their velocity significantly better than the flying trash cans. This extends long-range killing potential significantly. I particularly like the new Bonded ShockWave from T/C and the Barnes Spit-Fire MZ. These are tough bullets that shoot superbly in my test rifles.
Getting back to my friend and his new Encore: He insisted I shoot first to get the scope zeroed and determine the best load. The scope zeroed with only a couple shots because we had a large backboard to catch every bullet. Then I fired three shots, each loaded with two Triple Seven pellets and a 250-grain ShockWave. The group measured exactly 1 inch. "There's your deer hunting load," I said. "We got lucky and got great accuracy with the first try. But just for fun let's try three pellets." After firing a three-shot group using the 150-grain powder charge, we walked to the target. I knew the bullets had hit closely together, but was amazed when we measured the group. My three shots measured just under a half-inch!
At the range you must determine the loading procedure that works best for you. Uniformity is the secretâ€”do every step of your loading process similarly and good accuracy will be the result.
Rememberâ€”the more you shoot, the better you'll shoot, and this holds true for pistols, shotguns, rifles and muzzleloaders. Unfortunately, after I shot those groups for my friend with his new Encore muzzleloader, he proved this axiom. He sat down and fired three shots at the target and only one bullet hit the paper! Needless to say, he intends to do some practicing with his new in-line before taking it into the field.