Paintball anyone? I need some advise.

So, I'm not sure how to possibly "sugar coat" my question, so here it goes. We live in the country, in the woods and have a deer problem, go figure. All day they are running around, every time I come down the driveway I almost hit one and every night when I go to put the dog out, I have to run around like an idiot screaming to get them to run back in the woods. Once the coast is clear, I can let the dog go do his business. If I don't  and if he sees one, he instinctively runs after it. It's only a matter of time that they tangle and I don't want him to get hurt. 
 

I need some way to "deter" the deer from hanging out and lying around in the yard. My shoulder is shot, bad rotator & labrum, so throwing anything is out of the question. I have a Beeman pellet gun but that could possibly injure one of them, so I'm thinking about a paintball gun. It won't hurt them, but it might get them to consider not coming back if it stings enough. 
 

I don't know anything about modern paintball guns or markers as I found out they're called. Decades ago I had a cheap CO2 powered one that I did some target shooting with behind our old house. The new ones use compressed air from small attached tanks from what I've seen and look like they would do what I need. Does anyone have one and if so, how accurate are they at 60'-80'? Would it hit with enough force/energy to "pi$$ him off" and make him run? Hopefully never to return and go tell all his friends of the unpleasant experience he had at our address. 
 

Any insight would be greatly appreciated.

It's been several years, but 60-80' shouldn't be an issue, especially with a little practice. 

If the paint balls don't sting enough to deter them, freezing the markers will create a larger sting while still being non-lethal. 
 

Have you tried coyote urine? Or other predator scents around the boundary of the yard?

Last time I played paintball was in the early 2010s but a cheapo rental-grade "marker" would have a decent chance of hitting a deer at 60-80ft, I'd guess it would spray balls through about a 6ft circle at that distance. The ball speed used in paintball games is regulated down to 200ft/s muzzle velocity but they can be set much faster which will hurt more at longer distances.

They shoot like Star Wars stormtrooper rifles though. I remember one tournament I was in where the other guy tried taking cover behind a cone-shaped obstacle about 40ft away, most of his upper body was exposed and I thought, is this guy serious? So I aimed right at him and let him have it. Then I had to wait for maybe 4-5 balls to come out, helplessly watching them spray around the guy, until one finally hit him.

why not shoot them and eat them? Seriously. Venison is delish.