Archived from groups: uk.rec.shooting.game (
More info?)
In message <oTxec.32131$Y%6.4049762@wards.force9.net>, Michael Roberts
<mail@dogcountrysports.co.uk> writes
>I need to make a point to some of my customers who have been demanding 36gm
>and even 42gm cartridges for their 12g guns when pigeon shooting.
They're nuts, then. But how is your profit margin on the heavier
cartridges? (No, I'm not being sarcastic.)
Short answer: I have placed some comprehensive information of shotgun
barrels, chokes, shot sizes, patterns and patterning etc. on my website
as follows. Watch the word-wrap in the link, and it is case sensitive.
http://www.jonathan-spencer.co.uk/Reference/Guns/Shotgun/Ammo/Shotsize1.h
tm
Longer answer follows.
> (I manage
>perfectly well with 28gm cartridges in my 20 bore ).
Indeed, one can put as much shot as one likes in the wrong place and
it'll do no good but just a few pellets in the right place ...
>Has any one got some AUTHORITATIVE tables to demonstrate that the difference
>in killing range between a 32 a 36 and (if you have it) 42 is negligable
It isn't so simple: depends on what is mean by 'killing range'? Does it
mean for each individual pellet, or the pattern? What choke is being
used?
The effectiveness of the individual shot - lethality at any given
distance - is no greater from the heavier load, there is simply more
shot present and so the pattern is denser. That may be a good thing or
a bad thing depending on the gun's choke and distance the game is shot.
A 12 gauge gun that is bored, say, 1/4 choke should have *exactly* the
same diameter of pattern, and exactly the same density of pattern -
expressed as a percentage of the shot charge - as any other gauge gun
with 1/4 choke. So it follows that if A fires a .410 cylinder bored gun
and B fires a 12 gauge cylinder bored gun, the spread of shot at, say,
20 yards should be exactly the same diameter and there should be exactly
the same >percentage< of pellets within that diameter. Now, if the .410
fired 1/2 ounce of shot and the 12 gauge fired 1 ounce of shot, the
number of pellets within the 12 gauge pattern will be much higher. There
will be fewer 'holes' in the pattern and thus the 12 gauge produces a
'better' pattern. (Better is in inverted commas because the judgement
depends on the use to which the guns are being put, e.g. shooting rats
in a barn (the .410) versus snipe over a bog for the 12 gauge).
Yes, I agree, your customers are being silly and wasting their money,
putting their guns to greater stress and, no doubt, taking punishing
recoil for no good reason.
You asked for authorities. Chapter 12 "Choosing chokes and loads" of
"Shotgunning - The art and the science" (ISBN 0-8329-1840-7) is one
such. Gough Thomas' series of books are another. Eley is another. As
is Archie Coats' book on pigeon shooting.
Yes, choke is important. For shooting pigeons (over decoys?), cylinder
is appropriate. The effective range is 20-30 yards with a suitable
cartridge.
Gough Thomas said this (p210, Gough Thomas' Gun Book):
"... effective range of a shotgun ... is the greatest range at which the
gun can be expected to put a killing number of pellets into a given bird
when it is fairly caught in the pattern circle." And he goes on to
consider how many pellets are necessary to kill a given species (this
can also be found in the Eley Shooter's Diary). For pigeon it is three
medium sized shot. Thomas draws, in part, on the work of Maj. Sir
Gerald Burrard published in his landmark book "The Modern Shotgun".
The effective range means the gun & cartridge produce a pattern
sufficiently dense to ensure that enough pellets - having sufficient
energy to kill - will strike the chosen quarry when centred in the
pattern. So the shot has to be of appropriate size and velocity. For
pigeons, each pellet should have at least 0.85 ft-lbs on impact. Out to
50 yards, No 6 shot has over 1 ft-lbs, but it drops to 0.8 ft-lbs in the
next >five yards<. So - on paper - it would appear that the effective
range on pigeons could be as much as 50 yards. But it isn't, because
the patterns won't be good enough.
The theoretical patterns look like this (if the gun/cartridge
combination perform perfectly):
Percentage of shot
Range 30 35 40 45 50 55
Imp Cyl. 72 60 50 41 33 27
Half choke 83 71 60 50 41 33
Now, that table shows only percentage, it doesn't show the distribution
of the pattern, i.e. the quality of the pattern. Look carefully at the
figures and you will see that the patterns deteriorate rapidly, become
very sparse, beyond 40 yards. No wonder than, that after exhaustive
testing by the industry and game shooters through the 19th and 20th
centuries, the consensus of maximum effective range for a 12 gauge
shotgun loaded with 1-1/16 oz is 40 yards.
There is more to consider. A typical pattern produced on the flat
patterning plate will include some areas through which a bird can
'escape'. Many people consider that an empty 5 inch disc represents
a 'missed bird' (but see later). GT reported that the number of
non-overlapping 5 inch circles (the vital area of our pheasant) in which
there were no shot strikes on a normal 12 gauge 30 inch pattern were as
follows.
No. of shot in 30 inch circle
No. of 5-inch vacant patches
50 13-19
100 8-11
150 4-7
200 2-5
250 0-3
300 0-2
Of course, the pattern plate is 2-dimensional but the shot pattern in
the air is 3-dimensional, and shaped like a large sausage or melon.
Approximately half the shot is in the front third of the sausage. The
5-inch vacant patch represents a 'tube' along the length of the
pattern. Unless our bird is flying directly up that tube, he will be hit
by several shot – so the reality is better than the pattern plate
might have us believe.
Some manufacturers measure the quality of
their patterns only by the presence or absence of the 5-inch vacant
discs.
I can see why your customers are thinking that "more is better" but the
truth is that one ounce of number 6 shot is adequate for the task, if
they will only put it in the right place. They'd be better off spending
their money on some shooting lessons, by the sound of it.
--Jonathan
"Justice is open to everybody in the same way as the Ritz Hotel."
Judge Sturgess, 22 July 1928
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