Dont shoot much do you?
That would be about 2500 feet per second.
Actually, I shoot a lot. A .223 has a muzzle velocity of about 3,500 fps (have seen as low as about 2,500, and as high as 4,000). Now, 3,500fps / 5,280 feet/mile * 3,600 second/hour = about 2,386 mph (which I rounded to 2,500 mph).
Don’t do math much before smarting off, do you?