I'm good to 100 yards or so with my Super Redhawk .44 Magnum. Out of the box, the single action trigger break was too heavy for my tastes, but use of a Wolff spring kit from Brownell's brought it right down where I wanted: 2 lbs., 10 oz., with no other modifications whatsoever. The supplied Ruger integral rings have done a fine job keeping the 2.5-7 x 28 mm scope mounted in place, with no hint of movement.

I've found the older Winchester Platinum Tip 250 grain factory ammo to shoot inside two inches @ 100 yards from this Ruger from a rest, while my regular "go-to" handload has been the 240 grain Hornady XTP's for years. XTP handloads have done as well as 1-1/2 in. @ 100 yards, with 2 inch five shot groups being realistic.

Wow, a zombie thread comes back to life, and for the second time!

to the OP's question:As far away as you can put every single shot on an 8" paper plate. The limiting factor is your skill, not the gun.

Some years ago I was at a hunting camp and someone from the group before had left behind most of a box of 45 ACP 230 grain Remington Golden Saber's.

The guy who let us in said that the guy shot 5 times, hit the hog twice and both bullets had balled up in the gristle plate. They were in the bushes with a 175-200 pound hog at 25 feet.

this was a really great read

According to me, the effective range of the .44 mag is 100-150yds.