Basically what I'm going for is this...
I want a pistol which is unique in the respect that it has high energy, but not too high so that it hits me in the face.
One of my main problems which I wanted to solve, was the distances at which I have seen HUGE bucks on my property that were too far to shoot. Like 200-300 yards. Whitetail bucks. The property I hunt has little woods, and huge open grasslands. It is often hard to cross paths with a deer, but not hard to find them in the binoculars.
I know right now a bunch of folks just cringed that I would use this for whitetail. The fact is, we have to use straight walled cases of any length. Or, we can use a bottleneck up to 1.7" case length, which makes no sense at all to me. (Like saying, "You can either use a pellet gun or a cannon.")
Really, what I am seeking is a flatter trajectory. With the straight case rule, anything with a flat trajectory has no energy at these long ranges. Or, anything with energy doesn't have a flat trajectory. I wanted to counter both of these somewhat, so I decided I need a smaller diameter straight-wall with very high energy. I am trying to get as close to a performance rifle as I can from a pistol, more or less.
I have not used a chrono with a pistol shooting a rifle round, so I don't know what kind of loss I should expect if rifle energy numbers are 3500ft-lbs or so. Maybe 3000ft-lbs in the pistol? Not sure.
I would be using a laser rangefinder as well to get accurate readings.
Right now I think I am leaning towards an Encore pistol, but I hear the balance may not be good for large rounds like this. Competitor pistol could build me one as I hear they balance and shoot much better with the large rounds than a rear grip pistol. The only downside is Competitor pistols are butt ugly.
And Full-choke, Buffalo bore doesn't make anything for 45-70 at 3000fps+! Maybe you mean energy? They have a few 3500ft-lb loads I wouldn't mind trying in my 45-70 levergun. I use Buffalo Bore .45 Colt +P in a Ruger Blackhawk...it is fierce recoil from the small gun.