Rider Rifleman
Are you a Math Whiz? I’m not, and I have a problem I need to solve. It involves ballistics, and is a toughie.
In watching an old Clint Eastwood Movie, I caught a major physics error. Clint and some others are riding on a mesa, with mountains a mile or so away. Suddenly, we hear the thump of a bullet striking one of the riders, followed by the boom of a rifle shot. He falls out of the saddle, dead. The rifleman is perched on a mountain, and the heroes can’t hit him from that distance. More shots, and more “Splat-Booms” come. It ends when Clint remembers he has a rifle in a case near him. He fires once and hits the bad guy, who dies with a look of disbelief on his face. The problem is: As shown, there are no gun sounds until the bullet hits the man, followed by the report of the rifle. This establishes that the bullet is supersonic when it hits him. So, it would make a distinctive, loud “crack”, as it flew.(Sonic Boom) So: No Crack=Subsonic bullet. But, bullet arriving before report=Supersonic bullet.I am sure of the sequence of the scene, so this seems a huge goof. Am I right? If not, why?
Your question is rhetorical. It’s a movie, made to entertain the audience. Your keen observation has pointed out a flaw in the movie.
When you fire a gun, you hear it instantly, and the bullet is travelling X fps. As you know, when said gun is fired, there will be a gap (depending on the distance) of time between when the gun was fired and when it was heard from X distance. Sound travel…you know the physics in that I’d assume. In no way would I assume that in your example, a bullet will reach its target before the sound of the gun. Afterall, when is a .30 caliber, a .45 caliber etc. rifle bullet supersonic? NEVER.
Better yet, have you EVER seen a rifle bullet like the one used in the movie hit its intended target at THAT distance? It NEVER happens, especially with that type of gun and technology. The bullet drop at 200 yards is huge for a bullet at that size as used in the movie.
Check the ballistics of these cartridges at any manufacturer’s website… the FPS’s are CLEARLY below supersonic.
Don’t you just LOVE the movies?
The lonesome rider of Fallen Earth