The manuals don't even list Bullseye any more, so I would stick with an established shotgun powder.
Not to hijack this 231 thread, but ...
A couple of whiles ago, I had the occasion to talk to Ben at Alliant about a couple of loads and powders, and asked, specifically, abt Bullseye for light 12s, and if it had gotten caught up in the 'cleaner-burning reformulation' craze and was now chemically unsuited for 12ga use now.
He said, "Naw, it works just like it always has, but Bullseye was an 'old' powder and there was both: less demand and, frankly, Alliant marketing the newest.big.thing. certainly affected it. Lyman's and ABC's space is at a premium, and their pages are demand-driven, and ATK makes a lot more money on e3 and American Select than Bullseye ... besides, the pistol shooters buy all the Bullseye we can make ..."
I told him I was pretty conscientious abt tilting my barrels down after I shot a Bullseye load to let the cinders and clinkers fall out, and he told me that Alliant still recommended cleaning a shotgun once a year whether it needed it or not.
GS