Davems - I don't usually get involved in arguments like this one, but I admire your tenacity in trying to find out what you want to know, and I don't like to see someone treated rudely for asking an honest question. I have some experience with buckshot and deer and will be glad to share it. I grew up hunting in the 60s and 70s using buck shot on dog hunts. It was the way my dad hunted, and it was the only way anyone in our area hunted when I started. I killed 12 deer with buckshot and saw many more killed. I also saw a lot that were wounded and lost.
By the time I was 21, I had made the decision on my own that I would not hunt with buckshot again. I had a .308 by then and found it to be much more reliable for taking a deer. I did not use buckshot again until a few years back a friend asked me to test a new load he was developing. It utilized 5mm 18g/cc tungsten shot, and I was glad to try it for him. A couple of test shots showed that it shot very tight patterns at 40 yards. I shot a doe from a tree stand with it at 30 yards and it dropped her instantly. All the shot completely penetrated her, and a front leg was sheared. Here is a pic of what it did:
One poster in this thread said he would give up deer hunting if limited to buckshot. I wouldn't; I'd develop a 3.5" load using this shot and use it in my SBE with a Holosight on it. I'd test it to determine the max range at which I felt it would kill the deer 100% of the time, and limit shots to that distance. I don't know what that distance would be, but I think that 50 yards would be very possible. I think the tungsten shot might really extend the range of buckshot and make it far more lethal than anything you can buy. Since you are thinking of reloading, pm me if you are interested and I'd be glad to tell you what I know.
I have shot the 18g shot for 8 years now at turkeys, and it is miles better than anything you can buy. Of course, you kill turkeys by penetrating the Central Nervous System, (CNS), and deer are usually killed by the shock of a bullet taking out the vital organs. When a gobbler stands up straight, it is about 16" from the top of his head to the very base of his neck. That's a lot of CNS and gives the hunter a big target. Most turkey hunters like to count the number of hits they get in a 10" circle and consider 100 hits to be the max range of that gun, and I've found thats a good and reasonable standard to use. I think that you are trying to find a standard like that to use for buckshot and deer? It seems to be a very good quest to me to find that standard, and I commend you for trying to determine exactly how far you can shoot a deer and be sure of recovering it.
I would agree with most of the posters that you are better off to use a rifle if you can, but there are some places where they are not allowed. I hope you can determine a good answer for your question. If you go the route of the 18g shot, I think you would be better off to focus more on the CNS or bone structure of the deer than you normally would with lead buckshot. With the load I used, aiming at the front shoulder at 40 yards would not only put shot in the lungs and heart, but it will instantly break the deer down so it can't run. And even at that range, a shot to the neck would drop it just as quickly.
The test cited on page one of this thread has little to do with deer hunting with modern loads. The writer even said:
>>>>I brought some Wolf 00 Buckshot to the class.
As you can see, it holds 9 - 00 pellets and they do not have a filler to cushion the shot.
This tends to flatten the soft lead pellets and deform them as they go down the barrel.
This will open up the pattern more than other, better quality loads.
But I used this load because I had to shoot a lot of them, and they were cheap.
I figured they were good enough for practice, and they did just fine in that application.<<<
Trying to apply this test to your question would be like testing dove loads and saying a shotgun won't kill a turkey past 15 yards. I think it is setting up a Straw Man that one can easily knock over. Modern buckshot loads in guns with specialized chokes are capable of doing far better than the guns and loads of the 60s that I used, and the load of this test. And the idea that a 4" pattern should be considered the max range is one with which I disagree very strongly. My turkey loads have around 600 shot in them. I usually hit the turkey in the CNS with only 20 or 30 of them. My "kill" pattern at 40 yards is about 16" wide. To date, I have not killed any other turkeys, dogs, or hunters with the shot that miss the turkey, but I am very careful about when I pull the trigger, just as any hunter should be.
I think hunting deer with buckshot has enough issues that we can just honestly confront them. I guess some people see how buckshot has indeed been misused and just want to discourage all hunters from using it. I certainly share that desire to see every animal killed cleanly, but I think there is a place, a very small place, for the use of buckshot in deer hunting.
Let me say it one last time - I think that if you can use a rifle you should use a rifle. If you are hunting in a place that requires buckshot, do a lot of pattern work and then don't shoot one past the range that you are sure will make a clean kill. I know you want to do that, so I hope you can determine exactly what that range might be. Good luck!