Only with very high pressure loads. Normal pistol and cowboy loads do not generate enough energy. The very hot +P loads that can get a 260 grain moving at 1300fps. This will generate the energy to take deer.

http://www.chuckhawks.com/high-pressure45.htm

I have a Winchester '94 Trapper in 44 mag. A useful deer combination out to 125 yards or so. Though to be honest I prefer my Marlin 1895 Cowboy in 45-70. I have taken boar with 45-70 while the 44 mag stayed at home.

Pete