Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!tut.cis.ohio-state.edu!att!cbnews!military From: cfreund@PICA.ARMY.MIL (CCL-L) Newsgroups: sci.military Subject: Faster than a Falling bullet Message-ID: <13219@cbnews.ATT.COM> Date: 17 Jan 90 01:43:13 GMT Sender: military@cbnews.ATT.COM Lines: 32 Approved: military@att.att.com From: "Charles T. Freund" (CCL-L) RE: Falling bullets "Hatcher's Notebook" by Julian S. Hatcher, Major General, USA, RET Copyright 1962 contains a chapter entitled "Bullets from the Sky" which details a number experiments concerning the terminal velocity of falling projectiles. The bottom line is that most .30 caliber bullets will reach a terminal velocity of about 300 ft/s. Bullets falling point first will fall faster at first than bullets falling base first, but a 150- grain .30 caliber bullet tends to balance its weight against air resistance at a speed not to far from 300 ft/s. Tumbling projectiles start out falling slower, accelerating at a slower rate, but will level out at about 300 ft/s. Translating this, a 150-grain bullet traveling at 300 ft/s corresponds to about 30 ft-lbs. By Army standards, an average of 60 ft-lbs is required to inflict a disabling wound. Thus, a falling 150-grain .30 caliber bullet is not likely to cause a lethal wound. Will I stand under a falling bullet to prove this? Not likely! The lethality of falling projectiles increases drastically for larger calibers. An ordinary 718-grain .50 caliber machine gun bullets has a terminal velocity of nearly 500 ft/s and a final energy of just less than 400 ft-lbs. A 1000 lbs 12-inch shell will reach a speed between 1300 and 1400 ft/s and over 28,000,000 ft-lbs! Charles T. Freund US ARMY, Armament, Research, Development, and Engineering Center Picatinny Arsenal, NJ 07806-5000