Can you shoot 45 acp in a 45 long colt?

No, you cannot safely shoot .45 ACP ammunition in a .45 Long Colt firearm. The two cartridges have different dimensions, case lengths, and design specifications, which means they are not interchangeable. Attempting to use .45 ACP in a .45 Long Colt chamber can lead to dangerous malfunctions or damage to the firearm. Always use the correct ammunition specified for your firearm.