The Carcano is like most military rifles, in that it is sighted for about 250-300 yards, so that holding center of mass will create a casualty. This means that it will liikely shoot 8-10 inches high at 100 yards. It is possible to build up the front sight, put on a taller one, or regulate the load so that it hits to point of aim at 100 yards. The original sighting was for a 156 grain round-nosed bullet that was .268 in diameter. Note that most 6.5mm bullets are .264. At least one manufacturer makes a .268, which would bring out the accuracy potential. Loading a 100 grain or a 129 grain bullet will make it hit lower on target and get you closer to point of aim without having to alter the rifle.
The only time that the rifle would be a lost cause is if it is an early model that used gain twist rifling and was converted into a carbine by just shortening the barrel. In that case you need two nails to bring out the gun's potential. Hammer them above the fireplace and hang it above the mantelpiece.
Each gun is a law to itself. There are people who will tell you that a Carcano is a useless piece of junk, but it is what the Italian army used at a time when the U.S Army was armed with 1873 Springfields shooting a .45-70 loaded with black powder. Practice with the gun and it should do you well for what you want to do, without beating you up. If you do get a carbine, be sure to check the rifling, make sure the crown of the barrel is not buggered up, and that all the screws are properly tight. Good luck.