Back in 2001, I replaced the 29 inch full choke OEM barrel on my Browning A5 12 GA Magnum, with a Hastings Verny-Carron barrel. It came with three tubes. Full, Mod and IC.
I have used the shotgun with some success on Turkey here in Florida, with the Full Choke Tube.
I see they have an extra Full tube, and I was wondering if that would be worth buying.
I have been using Federal Magnum Turkey loads. 3 inch, 2 Ounce of #4 shot.

It's all about the amount of restriction. In my 12 gauge Browning's (Invector and Invector Plus) I have used the Pure Gold .670 extended tube and 3" 2 oz Hevi-Shot Magnum Blends - it has been a good combination for me out to 55 yards. With #4 lead I wouldn't go much below .670 in a 12 gauge. The tightest choke restrictions are for card shooters at turkey shoots shooting #8 & #9 shot. I see that the Hastings CT-II in Extra Full is .682, which is more open than their most open "Turkey Tube" at .675, so you should get a tighter pattern than with their Full tube and your load. Only way to know for sure is to pattern the load.

http://www.hastingsdistribution.com/index.php?l=product_list&c=26

true on patterning the load. I talked yesterday with a tech at Hastings. He told me that I would not gain much by going to the extra full with the load I am using. I'll probably go ahead and order the tube though. You never know.