_on Mr. Griffith’s authority_
┌────────────────────────┬────────┬────────┬────────┬────────┬────────┐
│ │ By the │ By the │ │ By the │ By the │
│ │fastest │next 25 │ By 45 │mean of │ last 3 │
│ │ 5 p.c. │p.c. of │p.c. of │ the │p.c. of │
│ │ of │pellets.│pellets.│ bulk. │pellets.│
│ │pellets.│ │ │ │ │
├────────────────────────┼────────┼────────┼────────┼────────┼────────┤
│15 yards choke (42)│ 1013│ 987│ 974│ 952│ 813│
│ 〃 choke (49)│ 1050│ 1013│ 1042│ 965│ 798│
│ 〃 cylinder (42)│ 1003│ 955│ 962│ 923│ 742│
├────────────────────────┼────────┼────────┼────────┼────────┼────────┤
│25 yards choke (42)│ 825│ 792│ 779│ 748│ 684│
│ 〃 choke (49)│ 890│ 840│ 806│ 809│ 699│
│ 〃 cylinder (42)│ 810│ 769│ 750│ 724│ 615│
├────────────────────────┼────────┼────────┼────────┼────────┼────────┤
│35 yards choke (42)│ 691│ 661│ 660│ 632│ 523│
│ 〃 choke (49)│ 737│ 699│ 699│ 672│ 564│
│ 〃 cylinder (42)│ 672│ 632│ 636│ 619│ 504│
├────────────────────────┼────────┼────────┼────────┼────────┼────────┤
│45 yards choke (42)│ 581│ 560│ 549│ 536│ 489│
│ 〃 choke (49)│ 633│ 598│ 592│ 573│ 527│
│ 〃 cylinder (42)│ 561│ 538│ 523│ 494│ 488│
├────────────────────────┼────────┼────────┼────────┼────────┼────────┤
│55 yards choke (42)│ 377│ 365│ 362│ 344│ 342│
│ 〃 choke (49)│ 478│ 462│ 457│ 427│ 418│
│ 〃 cylinder (42)│ 382│ 374│ 378│ 370│ 382│
└────────────────────────┴────────┴────────┴────────┴────────┴────────┘
As these are the only chronographic tests of shot pellets ever made with
a view of finding out what really takes place, the striking velocities
of the various proportions of the load at different distances are given
here. But although this represents the only use of the instrument for
this purpose, on truly scientific principles, ever recorded in print,
the author would be sorry to affirm the absolute accuracy of the
instrument on this or any other occasion, although the relative accuracy
of one record to the other is much more likely to be correct.
The (42) and (49), after the description of the gun in the table on p.
41 refers to the load of Schultze powder, and in all cases 1⅛ oz. of
shot No. 6 was used.
In order to arrive at striking velocity from these trials, it was
necessary to compare the time taken at one range with that taken at
another range by a different cartridge.
That in some cases the leading pellets are recorded as slower than those
behind them, is not, as would at first sight appear, an absolute
disproof of accuracy, because it may be that the leading pellets are
constantly dropping back, and others are becoming leaders. Obviously the
fastest pellets lose speed at the greatest rate, and obviously, also,
the leading pellets get least help and give most to their neighbours, by
setting up air disturbance, or a breeze, in the direction of the load.
We all know from paper pad and strawboard tests that the penetration of
pellets from the same discharge often varies as two to one. Some of
these records do not confirm this; but as they can only be accurate on
the assumption of that which must be true—the fluctuation of relative
positions of the pellets in flight—this adds to their value, because
that assumption is also required to explain the greater known variation
in penetration than the most indicated in these tables of speed.
The above remarks have been founded on the comparison of the
chronographic time of one load at one distance with that of another
discharge fired 10 yards farther away; and the mean speed over the 10
yards has been taken as the striking velocity at the midway distance of
the 10 yards. This is how Mr. Griffith worked out the striking
velocities. And from his figures the length of the shot column can only
be got at by making some use of a comparison between shots fired at one
range and those fired at another. In other words, the length of shot
column approximately found, as described, when divided by the difference
of time between first and last pellets, brings out the average
velocities of the shot column, at the instant of the leading shot
striking the target, too high. That is to say, the previous length of
column having been found too much, is taken merely as a basis, to
indicate the position in the rear at the length of the column away from
the target at which to search for the speed of the lagging pellets, and,
with these found, and the speeds of the leading pellets already found,
from the table upon page 41, the average speed has been discovered, and
actual time between first and last being known, the length of column has
been re-found in a way that must be as accurate as any records can be
that are based on two different discharges and the chronograph.
Taking the length of the column of shot, it is clear that the difference
of time in seconds between the first and last arriving pellets, divided
by the length of the column in feet, will give the mean velocity of the
shot column at the instant the first pellets struck the target. The
amended figures are tabulated on the next page.
It has lately been attempted to show that Mr. Griffith’s measurements
are not supported by the results on a target passing at 75 feet a second
at right angles with the line of fire. But this speed is not enough to
prevent the irregular spread of the shot pellets from misleading. In
other words, the faster the movement of the target the less will the
elongation of pattern depend upon the accident of pattern, and the more
it will depend upon the length of shot column and its speed. Besides
this, birds at 75 feet per second are not the difficult sort that people
want to learn to kill in a wind.
In the following table it is seen that in one case the column is no
longer at 50 yards than at 40 yards, and we may be quite certain shot
columns are not so in reality:—
┌──────┬──────────┬──────────┬───────────────────────┬────────────────┐
│ │Difference│ │ │ │
│ │of time of│ │ │ │
│ │arrival of│Length of │ │ │
│ │ first 5 │column of │ Mean velocity over │ │
│Yards │per cent. │ shot as │ length of column, and │ │
│ of │and last 3│corrected │striking velocity at a │ Description of │
│range.│per cent. │ by the │ point half the length │ gun and load. │
│ │of pellets│ method │of column of shot from │ │
│ │ in │previously│ the end of the range— │ │
│ │fractions │explained.│ │ │
│ │ of a │ │ │ │
│ │ second. │ │ │ │
├──────┼──────────┼──────────┼───────────┬───────────┼────────────────┤
│ │ │ │As found by│As found by│ │
│ │ │ │ time from │ time from │ │
│ 〃 │ 〃 │ 〃 │uncorrected│ corrected │ 〃 │
│ │ │ │ length of │ length of │ │
│ │ │ │ column of │ column of │ │
│ │ │ │ shot. │ shot. │ │
├──────┼──────────┼──────────┼───────────┼───────────┼────────────────┤
│ │ │ │ │ │Choke bore, 42 │
│ │ │ │ │ │ grains of │
│ 10 │·007 │ │ │ │ Schultze and │
│ │ │ │ │ │ 1⅛ oz. No 6 │
│ │ │ │ │ │ shot. │
│ 20 │·0145 │ 12 feet│ 1034│ 863│ 〃 │
│ 30 │·022 │ 16 feet│ 1000│ 726│ 〃 │
│ 40 │·036 │ 22 feet│ 777│ 619│ 〃 │
│ 50 │·046 │ 22 feet│ 630│ 489│ 〃 │
│ 60 │·054 │ │ │ │ 〃 │
├──────┼──────────┼──────────┼───────────┼───────────┼────────────────┤
│ │ │ │ │ │Choke bore, 49 │
│ │ │ │ │ │ grains │
│ 10 │·009 │ │ │ │ Schultze and │
│ │ │ │ │ │ the rest same │
│ │ │ │ │ │ as above. │
│ 20 │·018 │ 16 feet│ 1005│ 884│ 〃 │
│ 30 │·027 │ 20 feet│ 1000│ 768│ 〃 │
│ 40 │·0425 │ 27 feet│ 776│ 647│ 〃 │
│ 50 │·05 │ 28 feet│ 700│ 555│ 〃 │
│ 60 │·059 │ │ │ │ 〃 │
├──────┼──────────┼──────────┼───────────┼───────────┼────────────────┤
│ │ │ │ │ │Cylinder gun and│
│ │ │ │ │ │ 42 grains of │
│ 10 │·0117 │ │ │ │ powder and │
│ │ │ │ │ │ shot the same │
│ │ │ │ │ │ as above. │
│ 20 │·0222 │ 18 feet│ 990│ 812│ 〃 │
│ 30 │·034 │ 26 feet│ 823│ 769│ 〃 │
│ 40 │·049 │ 28 feet│ 714│ 583│ 〃 │
│ 50 │·057 │ 27 feet│ 526│ 484│ 〃 │
│ 60 │·057 │ │ │ │ 〃 │
└──────┴──────────┴──────────┴───────────┴───────────┴────────────────┘
The only way that this extraordinary result can be explained is this:
Mr. Griffith shot at his revolving targets set behind a hole of 4 feet
diameter made in a steel plate, and the question arises, Would not any
shot pellets that were only travelling at 382 feet a second drop out by
the force of gravity, and never pass through the opening at all at the
longer ranges? They would take a considerable fraction of a second to
reach the 55 yards range, and pellets would drop a foot by the force of
gravity in ¼ second, therefore some of them would not pass through the 4
feet opening. On this assumption, instead of the 50 yards columns of
shot being of the lengths stated, they must be very much longer, with a
continuous dropping of the weaker shot all up the range.
It is often asked how it happens that so few fast driven birds are
wounded. They are either killed or not hit as a rule, even when they are
high up. Another query is as often heard: “Why are fast birds more
difficult than slow ones?” It appears that one answer can be supplied
from the tables already given to both questions. It is often said that
it is difficult to lead “tall” birds enough, but the farther away game
is, the slower the gun has to move in order to race, and beat it, so
that this is evidently not the explanation. Taking the corrected length
of the various columns of shot at most of the ranges above 30 yards, and
comparing the average speeds of the fag end pellets, as given in the
table, with the distance they have to go, while the bird has merely to
go from 2 to 4 feet to get out of their line, it will be found that game
at 60 feet per second cannot get clear of any part of the shot column if
it is timed properly, whereas game at 100 feet per second will clear
about 40 per cent. of the length of column in some cases, and only incur
danger from 60 per cent. as he flies through it. This seems to be ample
reason for the greater difficulty of fast game.
Here are a few examples with the 42 grain charge: allowing 6 inches for
half the length of the bird, and adding this to the diameter of flying
shot column at various ranges, it is found that in order to get clear
while the shot column is passing, the bird at 60 feet per second takes
.041 of a second. At 100 feet rate of flight he will take .025 of a
second, and the shot takes but .022, so that the game does not get an
advantage here at 30 yards. But at 40 yards the slow bird takes .05 of a
second and gets no advantage; the fast one takes .03 of a second, and
here the time of the column is .036, so that, however good the timing,
the bird misses some shot. At 50 yards it is still worse for the slow
bird, which takes .062 of a second to get through, and better for the
fast one, that takes only .037 of a second, when the shot occupies .046
of a second for the whole column to pass.
There is not much difference for the 49 grain charge from the choke
bore. At 30 yards the shot column takes .027 of a second to reach the
distance after the first pellets are up. The 60 feet a second bird takes
.041 of a second, and the 100 feet per second bird takes but .025, or a
less period than the shot column. At 40 yards the slow bird takes .050
and the fast one .030 of a second, and the shot occupies .042 of a
second. At 50 yards the times are .062 for the slow bird and .037 for
the fast one, and the period taken by the shot column is .050 of the
unit of time; so that at the longer range the best timing possible would
only give the game 37/50 of the shot he would have as a slow bird.
The cylinder bore, with its longer column of shot and wider spread as
well, is a little different in effect. At 30 yards the period occupied
between first and last pellet is .034 of the second, and the slow game
takes .050, and the fast .030 of a second. At 40 yards .049 is the
period for the pellets; and .062 and .037 of a second those for the
quick and tardy game, so that there is twelve parts in every 49 of the
shot rendered useless in spite of the best possible timing and the
truest of allowances in front. At 50 yards the shot pellets occupy .057
of a second for the rearguard to come up to the distance, and the game
takes respectively .075 and .045 of a second for the slow and the fast.
So that, again, one gets all the benefit as if he were still, and the
other cannot do so under any circumstances.
In the last case, at 40 yards, every misjudgment of distance to allow
ahead by 1 foot is equivalent to .016 of a second off the total of .049
second occupied by the shot column, so that 3 feet of error will be
equivalent to a total miss for the slow bird, whereas for the fast bird
every foot of error is equivalent to .010 of a second, and 5 feet of
error in judgment in allowing in front, may enable you to hit with the
tail end of the shot column, but only to wound most likely.
The best shot gun experiments ever made with the chronograph, therefore,
show that if you have to aim 5 feet in front, and do aim 10 in front,
you do not necessarily totally miss at 40 yards; whereas if, instead of
aiming 5 feet too much in front, in like circumstances, the gunner aimed
5 feet behind, or, in other words, dead on the mark with a still gun, a
hit would be impossible: the game would never be in the line of the shot
after the trigger was pulled. This would be so, even although the gun
was following round with the bird; so as to ensure no loss consequent on
the time occupied by the pull of the trigger. It is clearly better to
aim greatly too much in front than a little too much behind.
Even before the author ever engaged in driving game, he had shot at the
first bird of a covey and killed the last one, 7 or 8 yards behind. In
shooting driven game this is not an uncommon experience for beginners,
and is a very useful lesson; for nobody has ever had the opposite
experience, and killed the first bird when shooting at the last. But
when this shooting at the pigeon and killing the crow occurs, it is not
always because of so vast a misdirection as is suggested. Five feet of
error at least may be accounted for by the longitudinal spread of the
shot, besides something more for the lateral spread. Indeed, two birds
in the same covey, one 8 feet behind the other, have been killed at one
shot; but it rarely happens. Nevertheless, when one of the two is much
the further away, as well as behind, then a bird a very much greater
distance than 8 feet behind the one shot at and killed, may also fly
into the shot, and die too. In practice, however, it is very much easier
to miss a whole pack of grouse that look to be near enough together to
kill a dozen at a shot. If one tries to do a bit of “browning,” it is
generally not the birds that are “done brown.” If it is not the survival
of the fittest that has evolved grouse that look so much nearer together
than they are, it must be a wise provision of nature in the interests of
sportsmanship.
From what has been said, it will be gathered that when game is crossing
fast, wounding is caused by bad timing. The game is either through the
shot column before much of it has reached his line of flight, or he has
not reached the shot column when the majority of it has passed his line
of flight. In either case he gets but a small proportion of the shot
pellets correct timing would have given to him. Wounding zones and
killing circles as applied to straight-away game have little to do with
it. Provided timing is right, superficial “wounding zones” help the
kill, because the game that passes through them also passes through the
bulk of the shot column before or after. Even patchy patterns on the
whitewashed plate may be quite evenly distributed to the game flying
through the section of the column of pellets. One thing that is perhaps
worth noting is that if the head of the column of pellets, or first
arrivals of the pattern, surround crossing game evenly, the bird will
have so short a distance to go that he may be out of the circumference
of the shot column before a quarter of the pellets have come up to his
line of flight, and if he loses a tail feather and drops a leg it will
not be because of a large wounding zone of shot in the superficial
target sense; indeed, a larger wounding zone of that kind might help in
such a case: the fault will be because the game had not to fly through
the whole section of the column of shot.