Roger46982:
I purchased a Knight Rolling Block last summer when prices were discounted. I put a peep/globe sight on it, but I have only had time to take it out to the range 1 time, so I have not had a lot of time to fine tune its accuracy. Overall, its accuracy was good on the first time out; no hangf fires, etc.; and I have every reason to believe that it will be as accurate as my other Knight rifles.
I was using Black Mag XP powder because I heard that Blackhorn 209 does not work reliably with the KRB. As you probably know also, Knight is no longer making muzzleloaders, but for the time being they are selling parts and providing service.
I have read other posts that praise its accuracy. The two possible negatives: it takes some time to clean the trigger assembly and it apparently it won't work with Blackhorn 209.
My overall assessment is that, if you're experienced MZ shooter (as opposed to a newbie looking for your first inline MZ rifle), this is a good MZ to have.