Re: Does anybody fowl their barrel before the hunt?
First cold clean shot is often at a different point of impact for a variety of reasons. Barrel heat, barrel fouling, a coating of patch lube on the bore, etc. Even the residue left after a wet then dry swabbing has certain moist lubricating qualities. Hunters worry about that first shot. Target shooters want the 4th or 5th shot through the end of the day to be as consistent as possible.
There are hunters that scrub their barrels clean with alcohol to remove all the oil before loading. A clean bore may offer ever so slightly different friction than a slightly dirty bore, or even a oiled bore.
I have heard of a guy that scrubs his bore clean and then runs a patch lubed with his patch lube down the bore with a jag. After he removes that he loads the gun. I guess the idea is to make sure there is a good coating of lube on the bore that might not be there with just loading after the scrubbing. Folks have tried all manner of things. I have found that the first shot usually has an impact about three inches from the point of impact for the third shot when bench shooting at 100 yards. By the fourth shot in target shooting, the barrel is warming up noticeably. In some weather the heat mirage off the barrel can hide a low front sight. If the point of impact is only three inches off at 100 yds, I'd use Kentucky windage adjustment. Have you checked to see if that first cold clean shot is at least consistent in where it strikes? I have an old trapdoor Springfield that I sometimes shoot in BPCR competition. The first cold clean shot is invariable off the left about 4 inches at 8 o'clock. The next shot comes in an inch, the next closer and by the 4th it is right on. I suspect that this in part due to the thin barrel heating up and warping slightly because of the constriction of the barrel bands.
If I keep up a steady rhythm, it stays on target. If it cools over a break between relays, it can require some warm up shots. Usually, muzzleloader barrels are to heavy to warp slightly due to heat. But after a couple dozen shots, the barrel can be warm, even warmer where the wood forearms insulates the barrel. Heat on the bottom cool on top, may raise the point of impact a bit, but not real dramatically.
How far off is your first cold clean shot?