Having a special "steel" barrel what kind of choke would you use for this if at all?
had a special steel barrel BPS and a .660 Primos Tightwad worked real good in it with Hevishot #6's,never did try any #7's
Does it use invector plus or standard invector chokes?
standard invector
The old Star Dot .667 chokes were great in that bore size. Indian Creek or Jellyhead would be a great start. The best thing about the ICs is that they will swap until you are satisfied.
I have an old A5 with a newer Japan bbl, but haven't considered taking it turkey hunting. Darn fine guns.