I'm sorry, but a Colt SAA just isn't the best weapon to use against Zombies, much less more powerful C-Virus monsters like Shriekers or J'avo. You need something higher capacity with a bit more oomph like...
Wait, nevermind... I uh, though we were discussing something else...
On second thought, the Colt SAA is an extremely icon firearm from American history, chambered in one of my favorite cartridges, the legendary .45 Long Colt. I'd love to own one myself someday, or at least one of the many clones or a look-a-like such as the Ruger Blackhawk.
Seriously though, it's a fantastic firearm which despite it's age, could still make short work of any resident evil you might face, undead or otherwise. Just ask Claire Redfield.