My Father-in-law and I got in a discussion today. He says a modern jet fighter can actually catch up to and be hit by it's own .50 caliber machinegun bullets.

I say that is a crock.

Perhaps if the cartridges being fired were .45acp but I still don't think so.

What are your thoughts on the topic?

This "wife's tale" has been around since jets were fist introduced. The physics simply won't work. You could be flying, say at a 75 degree angle, release a few rounds, go horizontal with full afterburner and perhaps be struck by your own bullets coming back down. That's not a very realistic concept though. Essentially bullets would be fired in some angle of attack that was plus or minus several degrees. You're NOT going to "catch up" to your own bullets. The bullet drop will take it WAY out of your path in short order. Remember, the muzzle velocity might be, say, mach 2.5 and your jet is flying at, say, mach 2.5. The bullet is REALLY screaming as you are adding both together. By the time the bullet has slowed to less then your airspeed, it will have dropped MANY, MANY hundreds of feet.

Ken....

Sounds like a case for the Mythbusters. Send them an email and see if they will take it on.

You married into that family. Good luck.

This is just like if I hock a loogie from the top of a tall building then throw myself off - will I catch up with it before we hit the ground?