I'm looking at a Super Redhawk Alakan for $700.00.
But it has the 2 1/2" barrel.
So I'm asking myself, "Yeah this would be a nice concealed handgun for shooting through engines . . . but how much of a big game gun would it be withthe 2 1/2" barrel?"

I see you can also shoot .45 LC through it. Would the .45ACP with appropriate moonclips work also?

The gun is designed and marketed as a packable gun for use against dangerous game in those "surprise, here I am" situations. It's not a top choice by any means for a primary hunting revolver.
If that's your need, and you think you need a .454 and a DA, look at the longer bbl Super Redhawks. I'd choose a SA myself but that's my chocie.
While the .454 SRH's will easily chamber and shoot 45 Colt cartridges, they will not accept moon clips for use of the 45 ACP.

I have a Ruger SuperRedhawk in 454 Casull it has a 7 1/2" barrel it is a big heavy gun and the reciol is pretty harsh with full power loads so with the short barrel I would say for emergency use only. I feel you should probably shoot a 454 Casull before you buy one as I said before they can be brutal to shoot I hope this helps chad

I'm quite accustomed to shooting my T/C Contender with the 30-30 barrel.
Now THAT will kick ya!
The .454 any worse?
Even taking into consideration the 2 1/2" vs. 14" barrels?

Yeah, I can't believe the 2 1/2" barrel is much good out past 10 - 15 yards. Just don't understand why Ruger would make such a thing.
Is it primarily a Griz protection gun?

As it's name kinda implies, Alaskan it's intended for use aginst those biggest and meanest critters that are in your area intent of harming you. Think of it asa CCW for the Alaskan wilderness.

A 2-1/2" barrel is totally worthless on a hunting handgun. It is ridiculous to put such a barrel on a .454 Casull-all you'd get would be flashburns from all that powder burning in the air after the bullet was long gone! A nutty idea, really! I have one with a 5.5" barrel, and THAT is too short!

.45 ACP in clips or ottherwise will NOT work in a gun made for the .45 COLT/.454 Casull cartridge. The ACP with clipshas way too thick a rim dimension to allow a .45 COLT cylinder to rotate in a properly set-up revolver, even if you could close the cylinder, which you could not do!

I own a contender in 7-30 waters and I will assure you that the .454 is much more of an animal than you would ever think.