Sept. 5, 1908.] 
FOREST AND STREAM 
39 1 
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COMPLETE SWEEP 
Made with 
AMMUNITION 
At Camp Perry 
Matches. 
PRESIDENT’S MATCH. 
WIMBLEDON CUP. 
HALE TROPHY. 
HERRICK MATCH. 
CHAMPIONSHIP REGT. TEAM MATCH. 
CHAMPIONSHIP COMPANY MATCH. 
INDIVIDUAL LONG RANGE TYRO LEECH CUP MATCH. 
LIFE MEMBERSHIP MATCH. 
97% of Contestants used 
AMMUNITION 
UNITED STATES CARTRIDGE COMPANY 
New York City San Francisco LOWELL, MASS. 
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€} 
( id different explosive^, and may be regarded as typical 
!i the forms assumed by the shot after emergence from a 
'rue cylinder and full-choke barrel respectively. These 
! vo particular records were obtained with the use of 
le experimental typically correct barrels belonging to 
le Field. The performance of these barrels, both as 
I ;gards velocity and pattern, has been accurately as- 
irtained by the Field experimental staff, and the pho- 
)graphs may therefore be accepted as representative 
f the performance of choke and cylinder barrels true 
> type. 
Passing to the detailed examination of the lllustra- 
ons, Fig. 1 represents the charge of l%oz. of shot 
! ropelleJ by 33grs. of E.C. powder from the true cyl- 
lder barrel. The coiled wire by which the discharge 
t the spark gap is induced at the moment compact 
I ; made with the straight wire is 25in. from the rnuzz'e 
f the gun. 1 he front face of the mass of shot is there- 
ire to all intents and purposes recorded at 24in. from 
le muzzle. The overshot wad flying in front of the shot 
i seen in contact with the spiral; it has a sharply de- 
! ned edge still remaining, and would appear, therefore, 
} have maintained the position in which it left the gun. 
tut it is a good deal torn and damaged, the paper 
overing the side toward the shot being evidently half 
irn off and opened up. The mass of shot is quite com 
act, and its front face shows a distinct outline of some 
;n pellets. The fcrm is not cylindrical, but more mg- 
estive of a truncated cone, with the card wad press- 
lg into the base of the cone, and being of smal'et 
) iameter than the mass of shot; in fact, at this distance 
om the muzzle, the diameter of the shot charge is about 
■ i per cent, greater than that of the barrel; but there 
; no dispersion of individual pellets so far observable, 
he felt wad follows at a short interval, and this, too, 
1 very nearly in a normal position; finally, the first card 
ad brings up the rear, and has obviously twisted to an 
ngle of about 45 degrees with the line of fire. About 
fin., to the right, that is to say, 3in. in front of the 
hot mass, the head wave of compression set up by the 
irward movement of the shot is seen as a thin curved 
ne. This and other waves and striations are very 
lear in the original negative, but become weakened in 
j re processes of block making and printing. The head 
; 'ave in air is only produced when the shot has a 
| elocity higher than” that of sound in air, viz., 1100ft. 
i er second, the writer having proved this point ex- 
erimentally by firing charges with a large proportion of 
| hot to the weight of powder, and therefore giving re- 
' uced velocities. It was invariably found that when the 
I hot had a lower muzzle velocity than 1100ft. per second, 
| tie head wave was no longer recorded. It is not un- 
easonable to conclude from the examination of this 
i lustration that the shot emerges from the cylinder 
I arrel in the form of flat-topped cylinder of the diameter 
j f the barrel, with at least the card wad close up to the 
[ ase of the cylinder. On the exit of the last card, that 
5 to say, the card' over powder, the powder gases 
1 merge from the muzzle at a much higher velocity than 
the shot, and press the wad next to the shot into closer 
and closer contact. The shot, being no longed confined 
in the barrel, is free to flow in a lateral direction, and 
the mass widens first of all at the base, leaving an 
annular area around the wad unprotected against direct 
gas blast. In the illustration, Fig. 1, there are to be 
observed a large number of striations parallel to line of 
fire surrounding the wads, and extending to a marked 
degree to about the center of the shot charge. There 
is little doubt that these striations are the result of the 
travel of the gas blast, more or less mixed with air, and 
that it is this gas blast which in the first instance causes 
the wad to expand the base of the mass of shot, and 
then at a later stage acts upon the unprotected annular 
area of the base, produces more dispersion, and finally 
gives rise to the wide dispersion and outside pellets 
observed at 40yds. with cylinder patterns. Fig. 2 shows 
the truncated cone shape of the shot mass in an even 
more remarkable degree than Fig. 1. In Fig. 1 the size 
of shot was No. 4, and in Fig. 2, No. 6, and this is 
probably the explanation of the more strongly defined 
enlargement, as it is reasonable to assume that the larger 
shot would be less easily deflected laterally than would 
the smaller. It may be remarked, en passant, that the 
overshot wad in Fig. 2 seen in contact with the spiral 
has evidently split right open and scattered many of its 
particles about the field of view. The particles specially 
noteworthy in this illustration proceed partly from the 
breaking up of the overshot wad, and partly from the 
paper tube of the cartridge case; they may often be 
observed when firing a gun in bright sunlight, and are 
not to be confused with solid particles of unburnt or 
partially burned powder, or mineral residue from ex¬ 
plosives of crude composition. 
If the above view is correct, then it follows that any 
device or procedure which will protect all or. any given 
proportion of the shot from the combined action of -yvad 
and powder gases will result in a reduced dispersion, 
and this is what the choke is calculated. to effect. The 
outer layers of shot, on meeting the resistance to their 
movement offered by the reduction of diameter, may 
naturally be supposed to be delayed in their passage, 
permitting the inner layers to pass through and out. 
When the whole of the shot has run the gauntlet of the 
choke, the wadding in its turn meets the obstruction 
and is delaved thereby for an infinitesimal period, but 
sufficiently long to delay the issue of the powder gases 
and to diminish the pressure of the card wad upon the 
base of the mass of shot. By the direct effect of the con¬ 
stricted diameter of the barrel the mass of shot has 
already been caused to assume a smaller diameter and a 
greater length than it does when propelled from a cyl¬ 
inder barrel; therefore less of it is exposed to the effect 
of pressure by the wad or the dispersing effect of the 
gas blast upon the basal portion unguarded by the wad. 
An examination of Fig. 3 supports this view. Here 
we find, as in Figs. 1 and 2, the overshot wad well 
ahead of the mass of shot, making the necessary elec¬ 
trical contact at the spiral for the production of the 
spark. The head wave of air compression is seen on 
the right close to the spiral. The mass of shot is utterly 
different in its form from the cylinder projection; . it 
occupies an actual length of l%in., as compared with 
J/^in. in the case of the cylinder. On the other hand, 
its diameter only very slightly exceeds that of the 12- 
bore wad. The shot pellets are only loosely grouped, 
and the card wad is not bedded against the base of the 
mass in anything approaching the definiteness observed 
in Figs. 1 and 2. The modelling or shading of the 
individual pellets is a curious effect due to the fact that 
the electrical spark is not a geometrical point, but a 
very short line, and therefore gives rise to penumbra. 
Very noteworthy is the absence of the clearly defined 
striations m the gases parallel to the line of fire, in¬ 
dicating that from the choke-bore the powder gases do 
not possess the energy in the neighborhod of the shot 
mass that they do from the cylinder bore. In a very 
large number of records this effect is consistently ob¬ 
served, and are now regarded by the writer as typical 
and constant. 
Of course, it is well known that a choke bore can be 
caused to produce abnormal dispersion by the use of an 
amount of powder considerably in excess of that for 
which the gun was standardized, and in the light of the 
knowledge now gained, this simply means that the gas 
blast from the muzzle possesses sufficient energy to 
overcome the delaying action of the choke and causes 
it to behave more or less like a cylinder. 
A subject of this sort opens up endless avenues of 
experiment and deduction, and I have not sought to do 
more in the present contribution than indicate broad 
lines and show typical results.—W. D. Borland in Field 
(London). 
Elgin National Gun Club. 
Elgin, Ill., Aug. 23.— The totals of to-day’s competition 
at the tournament of the Elgin National Gun Club, held 
to-day, were as follows: 
J Young .., 
Shot at. 
. 90 
Broke 
84 
F Ramm .. 
Shot at. Broke 
. 200 151 
J Barto .... 
. 90 
81 
J Graceley 
.200 
110 
W Burton .. 
Vietmeyer ., 
. 200 
187 
A Yolsch .. 
. 75 
52 
. 200 
184 
P Kemler . 
. 30 
17 
J Recli . 
C S Radew 
. 200 
16S 
J Morrison 
. 60 
26 
. 200 
171 
G Wardlow 
.... 45 
26 
H Vierke .. 
. 75 
60 
C Grunau . 
. 30 
20 
W Andrews 
... 110 
62 
A Tensen .. 
11 
C E Plum. 
. 185 
157 
C Burton .. 
.105 
76 
R Winters , 
. 210 
163 
L Freeman 
. 15 
7 
F Grimes .. 
. 75 
63 
G Cook .... 
. 75 
66 
T Pepple ... 
. 75 
56 
F Marsden 
. 30 
17 
T Lind .... 
. 2C0 
157 
No Name . 
. 15 
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