I/we kind of moved this post towards ballistics of a 12 gauge slug instead of fantasy deer kills at a 1/4 mile. I can use Devils info to get on paper a lot quicker at a range I have never tried.
Since no one has said it yet, I personally think it is bullshit if a deer was dropped over 300 yards, regardless of the ethics involved in taking the shot, even with a sabot.
But I am open to new things, so I may try some long shots on the range this year. The good thing about youth is when you are young, you don't know that "you are not supposed to be able to do that". The issue now is not rifled slug barrels, I have had mine for 20 years, it is the improved ammo. If Remington says 150 yards, that means 200. That is almost double of where I was hitting in 1983, when 75 was supposedly the max, I was at 120 yards. I have never bothered to go longer since then.
Hmmmmm?? First we have to get on paper, then do some research on retained energy at 200 yards+, then this fall one of us (the old farts) has to try a longer shot on a deer. 200 yards is not out of the question for a 50 cal muzzleloader.