Yours is the first post I read as I am looking for a good muzzleloader forum... seems you know your stuff and I can learn from your posts.
I justed purchased an Accura, shooting 245 power belt, 777 pellets, and Win. muzzleloader 209 primers... first shot is always off, after that seems to be on... I still need to find out my groups when weather breaks.
Very common. Some muzzleloaders need a fouling shot in order to shoot dead on. I personally think its due to a bit of oil in the barrel.
I also think you'd be MUCH better off with the Winchester 777 primers or the CCI Inline MZL primers.
I'll PM you a link on how to properly adjust the head space to keep the inside of your frame SPOTLESS.