This is just me ... when I shoot 777 powder, I swab the bore after/between every shot. The reason is Triple Seven in some, not all rifles, can create a "crud ring." A crud ring is un-burnt powder, burnt powder that is now a fouling substance, etc. And in some, again ... not all rifles, this crud ring can do a couple things; it can lead a shooter/loader of the next round to mistake a false base on the rifle. As the shooter pushes the next round down the barrel on an un-swabbed barrel, they hit the crud ring and can (and have) mistake the feeling for ... being at the bottom of the breech. When actually they are just slightly higher then that. That means the powder dumped down is not compressed in an equal manner to the prior load. This can lead to poor second shot accuracy, and possibly even damage to the gun technically. Although I have never seen that.
To stay consistent in our shooting, we must do the same thing over and over with muzzle loaders. So by swabbing the barrel each time, we do that. We consistently have approximately the same barrel conditions shot to shot. So technically we take some of the inaccuracy factors out of the equation.
As for things to use to swab with. Save some money. Go to the Dollar Store and get a cheap bottle of window cleaner. I use old T shirts, but some patches work nice too. Just spritz the patch and work that down and back up the barrel in three inches at a time sections. Then flip the patch over and do it all over again. The trick is ... don't saturate the patch but don't run a dry patch down a dirty barrel. Just a slightly damp patch works best. And in time and practice you will be able to feel and tell which patch is perfect. If you can ring water out of the patch do it, it was too wet.
After the wet patch then run a dry patch or two. Now you have pulled the fouling, and dried the barrel so it can accept the next powder charge without contamination. And I see as usual, I have been rambling on. Windex works real good and is much cheaper to use.
