From: watt-alan@net.yale.edu (Alan Watt)
Newsgroups: rec.guns
Subject: Re: Handgun Ammunition Debate
Date: 30 Sep 92 01:57:57 GMT
Organization: Yale University, Computing & Information Systems


In article <1992Sep28.213741.4849@henson.cc.wwu.edu>, n9020351@henson.cc.wwu.edu (James Douglas Del-Vecchio) writes:
|> Marshall ought to give, along with his "stop percentage", the percentage
|> of shootings with that round that he disgarded.
|> 
|> i.e.  	Fed 125 gr JHP .357	97%, "stopper"	with 99% disgarded.
|> 	Rem 33 gr HP .22 LR	100%,"stopper" 	with 99.999999% disgarded.
|> 
|> etc.
|> 
|> Jim Del Vecchio
|> 
|> 

Actually, he ought to do more than that.  I would like to see a distribution
of how many instances there were of each # of shots,  for example:

	Cartridge		1-shot	2-shot	3-shot	4-shot	5+-shot	total
	---------		------	------	------	------	-------	-----			
	Rem 33 gr HP .22 LR	     1	     3	     3	    17	     59	   93

It would also be useful to have the "non-stop" data, the cases where however
many shots *failed* to put the attacker out of business.

Now for a message from the real world.

People with statistics backgrounds can do all sorts of things with what
data are reported and how they are tabulated, but we will still face
uncertainties because of:

  1)	Bullet placement.  Marshall (I think) counts only center-torso
	hits in his studies.  This conforms to the standard doctrine
	of where you have the best chance of disabling an attacker.
	But you can't convince me that two solid pelvic area hits
	don't have an effect such that a single center-torse hit afterward
	is "more effective" that it otherwise would have been.

  2)	Multiple cartridges.  There are commonly cases where an attacker
	is shot with more than one cartridge type.  These tend to be
	the most interesting (from a stopping power theory perspective),
	because the attacker sometimes absorbs an incredible number
	of bullets from multiple officers.

  3)	Ammunition formulation.  This is not often mentioned in the
	debates, but the fact is commercial ammunition makers reformulate
	their ammo from lot to lot in response to complaints about
	performance.  If one agency says a given lot doens't cycle or
	eject reliably in their service sidearms, the manufacturer
	will change the loading to fix the problem.  If they get reports
	of failure to expand, they may change the bullet construction.

	Winchester Silvertip(tp) ammo for example, has been reformulated
	several times in response to performance complaints.  The
	Silvertip ammo you buy today may have very different characteristics
	from the same stuff available 4 years ago.  I doubt any agency
	is careful enough to record the lot number of the ammo used in
	shootings, and I don't know of any researcher who has been
	careful enough to group shootings in a given cartridge according
	to its formulation revision.

There is also a certain unreality to the Marshall definition of a "one
shot stop" which reminds me somewhat of all the attention in the Gulf
War to "where the Iraqi planes were".  There was a fixation on the fact
that U.S. forces could not account for the entire Iraqi air force, and
that somehow the inability to do so amounted to a U.S. "failure".  Finally,
a briefing officer got the point across.  He said: "how many U.S. aircraft
have been shot down by Iraqui aircraft? zero.  How many U.S. installations
have been attacked by Iraqui aircraft? zero.  How many U.S. air sorties
have been forestalled by the presence or threat of Iraqui air defences?
zero.  What effective contribution have the Iraqui air forces made in
countering the operations of any coallition forces? zero."

What counts is: after a perpetrator has been shot with a center-torso
hit, what percentage of the time does he continue to be an effective
aggressor?  In this context it does not matter if the perpetrator was
shot twice by an officer trained to do "double taps".  If he ceases
to be an effective aggressor, the shooting "stopped" him.  If he continues,
it failed.  Any time a perpetrator has been shot one or more times and
the responding officers observe he still willing and able to continue
aggressive action, the cartridge failed.  Any time a perpetrator is
shot one or more times and becomes either unwilling or unable to continue
aggressive action, the cartridge succeeded.

-- 
  Alan S. Watt
  Yale University			Computing and Information Systems
  Box 2112 Yale Station			(203) 432-6602
  New Haven, CT  06520-2112		Watt-Alan@Yale.Edu