From: crs@beta.lanl.gov (Charlie Sorsby)
Newsgroups: rec.guns
Subject: Re: Rifled Shotgun Chokes
Date: 11 Sep 92 20:12:00 GMT
Organization: Los Alamos National Laboratory

In article <1992Sep10.170929.9870@henson.cc.wwu.edu> you write:
= crs@beta.lanl.gov (Charlie Sorsby) writes:
= 
= #Considering bird shot, while even a two-foot pattern (if it were
= #possible) at close range would be very painful if it penetrated skin,
= #I don't believe that it would stop a determined assailant.  It is
= #arguable whether it would penetrate heavy clothing.
= 
= 
= How about heavy birdshot?   What are BBs, .18" vs .24" for #4 buck?
= I would think that would penetrate a leather jacket, fat, or what-
= ever standard psycho attire is these days.
= 
= The 7.5s and 12s and those little shots seem like big dust kind of, 
= but big birdshout out to behave differently, it seems to me.

Two things that I guess I didn't make clear:

First is that I don't believe it is possible to get patterns much
bigger than your fist at ranges one would normally encounter within
one's house.  So I personally don't see any advantage to going to
bigger shot because even the smaller shot is so concentrated as to
produce penetration (no, I haven't tried it but that's my belief--but
see below).

The behavior of shot is a function of its size.  The smaller the
shot, the more pellets there are in any given shot charge but the
less energy and momentum per pellet.  Because (with real shot) shot
size is not a continuum, we find these parameters changing by steps
but change they do.

Thus, as you mention, BB will be somewhere between, say, 7s and
00-buck.

My belief is that, at the ranges that exist within the house, one
is more interested in the behavior of the *entire* shot charge than
that of the individual pellets.  I believe this because I don't see
any way that at ranges from, say, 1 to 7 yards, you will get any
significant pattern dispersion (although, clearly, it will be quite
a lot greater at 7 than at 1).  Behavior with range, is of course,
a continuum, all else being equal.

At 7 yards, there may be some advantage to the bigger shot sizes;
at 1 or 2 I doubt that there is.  Just what the pattern diameter
will be at any given range will, of course, depend on many things
including choke, shot size, how hot the load is, etc.

My suggestion for anyone contemplating use of a shotgun for defense
(I only defend myself against game birds and clay targets so far
and I hope it stays that way) is that they pattern *their* shotgun
at various expected ranges with various cartridges including
various shot sizes, various shot charges, various powder charges,
various chokes (if that's an option), etc.  Ditto for penetration
tests.  Then you'll have some idea what to expect.

A final thought:  Don't think that just because it's a shotgun that
it won't penetrate the wall separating two rooms.  Try nailing two
pieces of dry wall to opposite sides of two 2x4s and shoot it at,
say, 10 feet with a shotgun (including the #12s that Jim mentioned).

And I repeat my earlier request:  If any of you try these
patterning and penetration tests with a rifled choke tube, I'd be
interested in hearing the results.


-- 
Best,

Charlie "Older than dirt" Sorsby				"I'm the NRA!"
	  crs@lanl.gov