Donald, The only way to find out how your gun would perform with a different choke is to try it. I've had differnet loads perform poorly from the same gun that shot another brand very well. I shoot a Benelli SBE II and it just doesn't like Remington shells for some reason. It also shoots 3" shells better than 3.5"s. I have three different turkey chokes (.650, .655, & .643) and each constriction produced a tighter pattern than the one before it. From my experience, a tighter constriction would help tighten your pattern, especially shooting #6s, but that's not always the case. I have seen a tighter choke cause an uneven pattern, particularly with bigger sized shot or harder shot.
A lot depends on your hunting situation too. I hunt a few spots that are heavy cover where too tight a pattern wouldn't work as well as a more open pattern does.
I hope this helps. Good luck this Spring.
Luck Counts, good or bad