Thats going to be a hard question to get answered. Mainly because of how the 327magnum was originally marketed.
Most of the 1st run 327's were chambered for short barreled revolvers.
2 or 3 inches.
The only 1st run 4 inch revolver I know of was the Charter Target Bull Dog that came with a 4 inch barrel.
That was a nice gun too. It was certainly on my to get list, but charter quit making them before I got the money saved.
Manufactures are just only now, ( with prodding) starting to see where the true market for the 327 is.
I am not sure what barrel lengths the Black hawk was made in. I suspect 5.5"
Guys that have them maybe can give you some details on game size.
Since the Single 7 we are now starting to see some work done hunting wise.
But with that gun the cylinder size is a limiting factor to creating the best hunting loads for larger game.
I suspect the top game size would be white tail deer. But I dont think any one of us are planning on trying it. Usually we have multiple choices and might choose a higher caliber.
So if my plans are any indication small to light med game for me.
As a matter of fact, that is what I use mine for. Head shots on Mr Rabbit are no problem. I stalk with 3 different loads in the gun. 32L, 32Mag and 327 mag.
I turn the cylinder to the appropriate load depending on range.
When I get out of Range for the 327. I shoulder my 32-20 rifle.
Fun package until I get my 327 carbine.
One of these days I will learn how to hunt Coyotes. We have them here, I hear them every night. But it is the rare hunter that actually gets one let alone see's one.