jlefud,
You said that you would like to be able to shoot and kill a bird out to 40 to 50 yards. I don't have a problem of taking shots at 40 yards however, when your talking 45 to 50 yards then you might have an ethics problem. Yes, your shot will travel that far but your ability to cleanly kill the bird drops tremendously. This is partly due to loss of velocity and also your shot string continues to disperse at the longer distances. I have a friend who is a game biologist and he has told me at a minimum a hunter needs at least 5 pellets in the spine and head of a turkey to kill it. He has cited a study his department had done on the number of wounded birds that was shot at 45-50 yards. The number of lost birds wounded yet were able to get away went up exponentially. What he was trying to tell me and the others in our group was that ethics should play a larger part in our hunting.
Now this is just my personal opinion but I hope you would consider working the bird in a little closer before attempting that long range shot and if you do decide to do that, please for the birds sake pattern your gun out at those distances and then decide if it is worth the risk of the bird getting away, crawling into a brush pile or hole and dying. Remember turkeys don't leave a blood trail!