I have a Ruger Blackhawk in .45 and I love it. But then, I also love the .22 Hornet. Both are guns (and cartridges) that take a lot of learning and experimenting to get the max out of them.
In the case of the Ruger, a Belt Mountain base pin is a necessity -- with hunting loads, the cylinder pin will simply back out under recoil.
In some cases, the chamber throats need to be opened up -- the chamber throat should be a thousandth or so larger than the bore.
For older .45s, you'll probably find the bore is somewhere around .454 diameter. For newer ones (built in the last 30 years or so), it will be .451/452. This means you have to get the correct mold for cast bullets, and if your gun is an older one, you have a handloading-only proposition, if you're interested in getting good accuracy. Factory loads with the correct size bullet will be hard to find.
The .45 Colt is really four different cartridges, and ought to be regarded that way.
For older six-guns, about 14-16,000 psi is the safety limit for chamber pressure.
For a little newer guns (like the Colt New Service and the various S&Ws), you can safely go to 23,000 psi.
For the Ruger Blackhawk, the T/C and a few other strongly made guns, you can go to about 32,000 psi.
And, of course with 5-shot revolvers like the Freedom Arms, you can load the .45 Colt to about .454 Casul levels.
At 23,000 psi, you can get 1,100-1,200 fps with a 250-grain bullet. That's fine for deer.
At 32,000 psi you can get around 1,300 fps with a 300 grain bullet (and generate so much recoil that very few people WANT to shoot your gun more than a few times at a session.)