Premium quality glass is a big part of it. Also, depends on terrain and even then, sometimes you have to wait for movement. It gets hard to tell the difference between a clod of dirt, or a rock, and a bean bear. I have one shooting friend that constantly says his glass is "good enough", but at half the magnification (24x). He's the first one to ask me if that mystery clump in the distance is a prairie dog. I have the luxury of being able to crank my optical zoom up to 42x (when weather and atmospheric conditions allow) and watch the "clump" for a few moments. Then, if it's a dog, I follow that up with a "boom", and a flat reply that it was indeed a prairie dog. Which usually got me cussed at by my buddy. Lol.
If you can't see them, or identify them, then you have no chance of hitting one, regardless on what caliber/ammo combo you're using.
I also personally wouldn't shoot a moose at a thousand yards, regardless of rig. With a prairie dog, and a "large" (relatively speaking) caliber dog gun, a hit is a kill due to how large the bullet + energy level is vs. how small the target animal is. With a big game animal, there's too much risk (in my opinion) of a wounding shot striking the animal and not killing it at those kinds of distances. Just too much body area you can strike that won't kill it. Not trying to start a debate on "ethical distances", but that's my opinion, and how I call my own shots. For me, my longest elk shot (similar body size to a moose) was 350 yards and I smacked her (cow) down hard with the first and only shot from my 338 Win mag. She never twitched or stirred after the bullet struck her. Plenty of energy present at that distance for a quick, killing shot (with proper bullet placement obviously). I used to say that 338 killed elk like The Fist of God.
