The maximum effective range of a .45 caliber bullet is approximately 120 meters.
25m
Probably. It would likely refer to a handgun that fires a .45 caliber ACP, or .45 GAP or an older .45 caliber revolver round.
@ 50m
45 has the larger projectile. Size of the handgun will vary.
1/4 mile plus- the EFFECTIVE range is about 50 yards
200
Either platform can be larger than the other. The 45 has the larger projectile. Caliber is defined as the diameter in fractions of an inch, so .40 caliber is smaller in diameter than .45 caliber. Caliber can also be defined in the metric system, measured in milimeters. The .40 caliber cartridge is equivalent to 10mm in diameter. As noted, the size of a handgun can vary widely within one caliber, so it is perfectly reasonable to have a smaller handgun crafted in a larger caliber.
In most circumstances, no. The bullet is too large to chamber in the handgun.
A .45 caliber Colt revolver- a handgun.
Best to ask a gunsmith for help
Which .45 handgun are you referring to? The .45 Colt revolver (Peacemaker) goes back to about 1873. The traditional "45 Auto" was adopted by the US Military in 1911, but there were other, earlier .45 caliber automatics. And of course, .45 caliber black powder ball and cap pistols, ball and cap revolvers, etc are MUCH earlier than the Peacemaker. So... which handgun?