The .45 ACP was designed by Browning himself in 1904 for his famous 1911 pistol; this particular round has a rich history. This is a large bullet and has stopping power that suits its caliber. For countless police officers as well as military personnel, the .45 ACP is the ammo of choice that has managed to prove itself time and again.
Pros: Strong stopping power, not very expensive and there are few firearms that can chamber this cartridge. Hit a target in the center mass with this round and you have a guaranteed drop. If they happen to be on drugs it may take about 2 shots, this round is meant to stop targets in their tracks, nothing more to say about it.
Cons: In the case of magnums, high stopping power means stronger recoil. Speaking from firsthand experience, a weapon that uses this caliber isn’t meant for a person that’s never fired a firearm before. For more experience users, note that this round, once fired, tends to begin tumbling at about 75 yards reducing its effective-range significantly. If the weapon is meant for self-defense, that’s not really a problem, but if you like shooting targets at long range, this round is not preferable.