You won't be sorry, I promise! We tried 120 grains, 90 grains, and 110 grains. In the end the grouping with 120 and 110 was nearly identical so we went with 110. With 90 grains we had a surprisingly big group but with 110 grains of BlackHorn and a 250 grain Barnes TMZ we got quarter sized groups at 100yds.
Once we settled on that we shot at 150 and 200 yards. 150 had an 8" drop and 200 had an 18" drop. We were sighting in the muzzleloader around mid December after Russ missed with the gun at 150 yds during 1st shotgun. The days we were at the range sighting in it was freezing! The other guys would shoot a couple, clean/swab, reload, shoot. Here we sat across the bench shoot, reload, shoot, adjust, reload, etc. No cleaning in the freezing temps. They kept asking how we were shooting like that without cleaning? In the end we were sold on the powder! We had put 20+ shots through the gun multiple times without cleaning and it shoots the same everytime.
And on Jan. 5th with the same gun I got my chance to take a good buck at 195 yards and the gun performed just like you'd hope!
No problems with humidity or moisture. Kept the gun cased when brought inside or would leave it in the truck. Mostly for ease of mind vs. taking it in the house and back to the woods the next day. I'm curious to pull the opened containers of Blackhorn out in a few months and see how sitting on the cabinet shelf affected their "punch".
I might add that keep an eye out..that the first shot out of a clean barrel MAY be off due to cleaning. Some people fire primers through, others a fouling shot with full powder and bullet to "dirty the barrel". Some of our muzzleloaders seem to shoot different that first shot down the clean barrel and others aren't affected. For ease of mind before we go hunting we'll shoot a full live round into a dirt bank, reload and let it sit until season is over or better yet we can drop the hammer on some deer!