I've found 3 inch Winchester HV with a 1 7/8 oz load to out perform the 2 oz load. One of those situations where "less is more" and its flying at a higher velocity. It takes less work for the same powder charge to send the lesser load down the barrel. The lesser load also accepts constriction in the choke tube better preventing the load from spewing, keeping a tighter patern. A tighter pattern with conetic energy = a deader Turkey

These folks will turn you a custom tube for about 2/3 the cost of the big name brands, mine shoots an awsum pattern.

http://www.wilsonprecision.com/index.html