Either one will work fine.  What you need to to is set up a target and look at you grouping and then decide for yoursel witch one you want to go to. 

What kind of range will i get with a 3" BB or BBB do you guys think

I will tell you that I use #2 stell all the time and have had great results.  I even use 2 3/4 for geese all the time in my 12 gauge and have killed many a bird at 40 yards.  I reload my 10 gauge with #2 steel and it is absolutely devestating.  I like the more pellets in the air.

You really need to get youself a few pieces of cardboard and set them up at different ranges.  Start at 40 and take a shot to see just what your pattern is and how many pellets hit the kill area.  Then work your way out as far as you are getting a good pattern.  All shotguns are a little bit different in the way that they throw the shot pattern that and depending on what choke you have in the barrel will make a difference.

I 2nd the patterning thing, that will tell you all you need to know and which load will work best.

The patterning is important.  You would never go hunting with a rifle you didn't sight in and the shotgun is no different.

i use bb and bbb in 3" in my 12 gage and  3 1/2 bbb in my 10 gage the birds just fall "no extra flapps or nothin". it also depend on how your huntin, in a ground blind in a field the birds are pretty much in your face with shots no more then 25 yards i use a mod choke for that but on a river or open water i go full choke for farther shots usally good out to 45 yards or so. 

I agree with the need to pattern the gun. Different sizes of shot pattern differently in different barrels and chokes.  I shoot hevi shot 3 inch no. 2 shot and have kill cleanly geese at 60+ yards!

I never use a choke over modified with hevi shot. I shoot a over/under and use improved cylinder and modified ckokes. Some complain about the high cost of tungsten blend shells but I figure that I do not shoot enough shells to mind the price.

I would pattern you gun @ 40 yrds with the loads you intend on shooting. As far as range of the 3" BB and BBB, you may get a few "GoldenBB's" to break a wing or in the head of a goose at 50 plus yard but your best bet would be to shoot them at 40 or closer, especally on Canada geese, they are a lot tougher than the Snows are....

I use 3 inch all the time for geese.  BB or T shot work fine.  I've never patterned any of my shotguns and as long as I do my part as a hunter/shooter I always knock em dead out fo the sky.  I typically use Xpert, Federal steel, or Remington steel and never noticed a difference in performance.  Just do your part and get em in close and you should be fine.