S8 
FOHEST AND STREAM. 
[July io, i9,ui. 
The Recoil of Shotgfuns. 
^ Mr. E. W. S. Griffith delivered a very interesting lecture 
;beofre the members of the Gunmakers' Association June 12. 
iHis subject was the recoil of shotguns, and he dwelt with it in 
■an exhaustive manner, which left little or nothing untouched o'n 
this important side of ballistic problems. At the outset of his 
lecture he showed a series of very interesting photographs deter- 
iiunnig the photographically visible deflection of the shotgun and 
the person shooting it during the act of firing. We reproduce 
herewith one such photograph, together with four smaller views 
showing the characteristic movement of the muzzle for four differ- 
ent classes of powder. These photographhs serve to convey in 
the clearest possible manner that even when absolutely the same 
duty is secured from the gun there is an opening for wide varia 
tion in both the amount and character of the recoil that is expe- 
rienced. That this is so may be inferred from the fact that the 
cartridges fired in the course of this photographic experiment 
were loaded so as to impart identical velocities to a uniform 
charge of shot. It was the powders which represented the only 
source of difference, and the extremes arc represented by No 6 
black powder on the one hand, the charge being 3%drs., and 
at the other end of the scale a 'i'igr. charge of imperial Schultze. 
It is quite clear from these photopraph.'. that recoil is determined 
RECOIL OF GUN AND SHOOTER. 
When firing S^^drs. of black powder from a 61b. gun, witli VAoz. 
charge of shot. 
by something more than the reaction due to the movement of a 
given charge of shot. Scientific laws tell us that action and 
reaction are equal and opposite, and yet we know that equality 
does not exist as between the forward action of the shot and 
backward movement of the gun. This does not, however, prove 
that the laws of motion are inaccurate, but only that this appli- 
cation of the law is incomplete. When, however, we bear in mind 
that the equality which exists is in reality that of the movement 
of the gun on the one hand and of the materials ejected from the 
gun on the other, we see at once that the movement of the 
shot is not the only forward action which must be taken into 
account in determining the equal and opposite reaction of the 
gun. All this .is the A B C of recoil, and has been insisted upon 
by all competent authorities for many years past. 
The consideration of recoil, therefore, comprises a careful estima- 
tion of the values of the various forward moving materials other 
than the shot and wads. The chief among these is the charge 
Cc) (d) 
1^ MOVEMENT OF MUZZLE. 
(a) With 2?4drs. of No. 2 black powder. 
(b) With S^Adrs. of No. 6 black powder. 
1 (c) With 42grs. of Schultze. 
(d) With 33 grains of Imperial Schultze. 
of powder, which obviously produces its due proportion of the 
recoil of the gun during its progress from the cartridge to the 
open air. Up to the time when the shot leaves the muzzle the 
powder gases and solid residues have spread themselves over the 
whole length of the barrel. Consequently their center of gravity 
ties at or about the middle of the barrel's length. We, therefore, 
appreciate that up to the moment when the shot and wads have 
reached the muzzle the charge of powder, whether 3%drs. of black 
or 33grs. of Imperial Schultze, has moved half the length of_ the 
barrel, viz., about 15in. Supposing that the shot has attained 
fl velocity of 1,200ft. per second, the gases have an average velocity 
of half this amount, and we must, therefore, add to the value of 
the shot's movement a further value derived from the weight of 
the powder gases and tlieir average velocity. This enables us to 
obtain a correct estimation of the recoil energy which, has beeri 
produced up to the point of time or distance of recoil represented 
by the arrival of the shot at the muzzle. 
Having granted that the center of gravity of the powder gases 
ie in a position at or about the center of the length of the barrel, 
we must also recognize that further recoil will be produced while 
this gas is getting free from the muzzle. In the ordinary way one 
would not suppose that the recoil produced by such a light body 
a« is represented by the products of combustion of the powder 
charge would be of very great importance in relation to that 
produced by the exit of the shot and wads, which has a weight 
from ten to fifteen times greater, according to the particular class 
of powder used. Experiments have however, clearly demonstrated 
that the recoil produced by the exit of the gases is at least equal 
to half that produced up to the moment when the shot leaves the 
t^arrel lo order to account for the production of a relatively 
Diagram of target, full size, made at the "Navy and Army" trials, at Cricklewood, England, with a .310 Greener rifle, at 100yds. 
high recoil from a body of such small weight, we must obviottslv 
assume that its velocity of movement is considerable. Kor the 
convenience of examining this aspecl of the question, we must 
treat the powder gases as concentrated around their center of 
gravity in the form of a pellet. This is a quite common method 
ut dealing with problems of motion, and it is the only one which 
serves to give a concrete idea of what happens during the exit 
of the powder gases. Taking the length of the barrel at Win., and 
assuming that the powder gases are centered around a point 15in. 
up the barrel, we can at once conceive the idea that this con- 
centrated pellet of powder gases has to travel a further 15in. in 
orda- to get clear of the muzzle. Assuming this condition, wc 
can at once calculate the velocity with which this amount of 
matter must leave the barrel in order to produce any given value 
of recoil. Several calculations which wc have made show that 
this velocity is somewhere about 3,000ft. to ■1,000ft. per second, the 
velocity varying with the character of the powder used. It is 
guite conceivable that the velocity of the gases mieht well approx- 
imate this value, since obviously the removal of the resistance 
offered by the shot would enable them to expand at a materially 
increased rate. The analysis of this expansion of the gases is a 
somewhat complex subject, because the forward portion of the 
gases immediately to the rear of the shot would leave at very 
much the same velocity as the shot itself. Immediately, however, 
that these gases get past the muzzle they expand, so forming a 
ball of high pressure gas around the muzzle. This partly checks 
the exit of the gas still remaining in the barrel. Yet, on the other 
hand, promoting the exit is the large amount of force which 
previously was strong enough to impart to the shot the velocity 
with which it left the muzzle. 
At any rate, what has been said is quite sufficient to make it 
clear that every part of the column of gas in the barrel leaves the 
muzzle at a different velocity, and if we know the combined effect 
of all these velocities we can arrive at an average value for the 
movement which occurs. Thfe average velocity so obtained may 
be worked out in combination with the weight of the products 
of combustion, which is obviously the same as that of the powder 
gases. This enables us to understand why the gases are responsi- 
ble for such a large proportion of the total recoil, and to appre- 
ciate the fact that their rapid exit involves a sudden acceleration 
of recoil velocity. 
What has so far been explained brings up to a consideration of 
the character of the recoil which is set up in fire arms. While 
the shot is in the barrel and the movements that occur are 
comparatively slow the recoil on the gun is also of a steadily 
increasing character, so much so that this portion of the recoil 
■ has been termed the "push" stage. Admittedly the gun travels 
about one-third of an inch during the push stage of recoil, repre- 
.senting a gradual building up of recoil velocity, which enables 
.a properly held gun to bed itself firmly in the shoulder. After the 
shot has left the muzzle the velocity of the powder gases in their 
.exit is so considerable that the whole of the remaining addition 
to recoil is produced during the short period of time represented 
by the movement of gases traveling at a considerable velocity over 
the very short distance of 15in. Here then we gain an apprecia- 
tion of the second stage of recoil, which has been aptly termed 
the "kick." . 
The gun has recoiled barely half an inch in all -when the forces 
producing the movement have ceased to operate. The remainder 
of the recoil shown in our illustrations is merely the result of the 
momentum imparted to the gun over its first half inch of travel. 
There need be no hesitation about accepting this statement. Mr. 
Mjixim has so arranged his automatic gun that the parts recoil a 
bare one-eighth of an inch while the shot is in the barrel, the 
remainder of the movements involved in the automatic recoil 
being produced by the energy imparted diiring the first short 
stage of initial travel. 
It will be interesting, in concluding this first notice of Mr. Grif- 
fith's lecture, to mention in a general way the various develop- 
ments which have brought us within reach of securing absolute 
values for recoil energj'. The name of the late Dr. Walsh was 
freelv quoted bv the lecturer, who referred in detail to the close 
scrutiny to which he had subjected problems of recoil. In the 
■ same way reference was made to the late Mr. Toms' mathematical 
deductions, which were also effective in placing the matter upon 
an exact basis. No pains were spared in experimentally investi- 
gating numerous aspects of tlie question, and the Field recoil 
guUge was the means by which these deductions were reduced 
to practice and definite measurements of recoil were taken. The 
latest form of the Field recoil gauge was described in our columns 
about eighteen months ago, and a correspondent thereupon wrote 
to us calling attention to the velocity method of taking recoil, 
which was calculated to lend itself to more exact application for 
mathematical calculations. This method was very ably investigated 
by Capt. Journee, of the French Artillery, who published the 
results of his researches in a brilliant paper appearing in the 
Memorial des Pondres in the year 1890. Capt. Journee adopted the 
principle of a freely-recoiling gun suspended at either end by 
means of two strings. He took the velocity of recoil of this gun, 
and his investigations supplied us with exact values for recoil of 
a character likely to be of great service in mathematical analysis. 
No experiments of the same character had been conducted in this 
country following the lines laid down by Capt. Journee until 
Mr. Griffith himself decided to take up tlie running. It is the 
result of his experiments with modern explosives that he com 
niunicated in his lecture. Briefly, the result of these experiments 
is that we obtain an absolute value for recoil up to the moment 
when the shot leaves the muzzle, and an equally accurate reading 
of recoil after the departure of the gases. These two measure- 
ments give us an absolute relation between the push and the kick 
.■stages of recoil. A further series of measurements tells us the 
distance the gun has recoiled during the push stage, while calcu- 
lation and experiment combined inform us what is the amount 
of additional recoil during the kick .stage. These four factors 
enable us to construct a curve of recoil in which the four leading 
points of interest are fully establishhed. 
We propose to examine in greater detail in our next issue the 
series of curves which have been so produced. The interest about 
them is that each curve establishes the characteristics of each 
powder during the kick stage of recoil, and these special character- 
istics can be mathematically handled so that they may take a 
definite place in a recoil formula which has been worked out by 
Mr F. W. Jones. From this it is evident that, once the "con- 
stant" of any given powder has been definitely established, the 
value of the recoil of any given combination of gun and loading 
can be mathematically worked out, with every certainty that its 
deviation from experimental results will be but normal. 
Our illustration of Mr. Griffith's appaiatus shows its more 
essential parts. The trigger is mounted with a long arm, which 
can be operated by an electrical magnet without altering the 
position of the gun. The method of suspension by strings works 
80 perfectly that the gun may be swung by the act of blowing 
against the muzzle. At the rear of the gun and beneath the stock 
IS a brass rod which breaks a series of electrical contacts during 
lhe recoil. The time elapsing between the breaks is registered, 
;md the interval of space between the contacts provides the where- 
withal for taking the velocity over any given stage of recoil. The 
muzzle velocity is simultaneously observed so as to obtain an 
indication of the energy imparted to the shot. It should be 
mentioned that an ingenious arrangement, not appearing in our 
illustration, is used for catching the gun after recoil. — London 
Field. 
Boston Gun Qtib. 
l^osToN, Jul)' 10.— Wednesday, July 10, was just Al conditions, 
and the second last serial prize shoot of the Boston Gun Club was 
a most delightful occasion. Shooters seemed to come from every- 
where, all bent upon one object, that of trying their hand at 
smashing the evasive bluerock, though not to compare scores with 
those ot the American team, just lately returned with highest 
honors. To be sure, we did not have the pleasure of any of their 
company, though we did have a most representative New England 
gathering, from the expert at 31yds., to the .imateur of lesser skill 
at 14yds. Both seemed to derive just the kind of enjoyment that 
is intended to be coupled with trapshooting, and that the handicap 
had put the two classes as near an equality as possible can easily 
be seen by comparison; 21yds. seems quite a handicap for any 
shooter, but it was not too much for the expert who stood on 
that mark to-day, as in five events, three of which were jiairs, just 
37 out of 50 were centered in truly top-notch style. The prize 
match, which now is at its height, was the center of interest a.s. 
usual, eleven shooters completing the events, with Dennison and 
Horace in the lead with 23, though very little separated Martin 
from the coveted position, 22 being his efforts. Barry was next 
with 21. Howe and Ford fourth with 19. 
Scores follow. All shooting handicap distance, unknown .mgles; 
Events: 1 2 3 4 5 6 7 8 9 10 11 12 13 
Targets: 10 10 op 5p 15 5p I 10 15 5p 10 10 lO- 
Martin, 18 10 9 5 8 13 ft . . . . 15 
Howe, 19. 7 9 6 9 14 5 6 
Dickey, 21 9 8 (i 7 .. 7 
Dennison, 18 S 9 7 6 14 9 5 9 1,1 7 9 8 8 
Frank, IS t 9 6 6 10 7 6 6 13 4 (5 8 10 
Barry. 16 7 10 7 5 13 7 5 9 12 
Nelson, IS 0 
Poor. 16 3 4 5 3 4 .5 .. 4 « 
Benton. 14 5 5 5 3 6 5 7 "7 
Horace, 18 10 6 6 15 8 5 8 12 8 
Retwood, 14 G 3 3 3 
Ford, 16 7 6 11 8 3 9 K 
Spencer. 18 ti . . 7 11 3 9 9 iiD 
M £ P, 14 3 6 .. 5 2 .. 
Frederick, 14 .S . . . . 
Henry, 16 4 . . 
Prize match, 25 unknown— 15 singles and 5 pairs^handicap dis- 
tance : 
Dennison, 18 .11111] 1111 11011 1111 01 11 lJ-^23 
Horace, 18 lllllllllllllU 10 11 11 II ltV-2:i 
Martin, 18 101111111111101 11 10 11 II 11 -22 
Barrv, 16 101111111111101 11 10 11 11 10 21 
Howe, 19 llimimOllU 11 10 10 10 tHI-19 
Ford, 16 i 111011111101001 1110 10 1111-19 
Frank, 18 111011011110010 11 01 11 01 01-17 
Spencer, 18 ......110011111101101 00 10 00 10 10— f t 
Benton, 14 100100010011010 00 11 11 00 10—11 
Poor, Ifi 001000000101100 00 00 11 10 11-- » 
Retwood, 14 100010100010101 10 00 11 00 00— 9 
Fltchbutg— Leomiastet — Gardner, 
FiTCHBDRG, Mass., July 11. — The third of the tri.wguUir contest* 
between Gardner, Leominster and Fitchburg was shot yesterday 
afternoon on the grounds of the Leominster club. This was it 
beautiful summer day — cloudy off and on, with a light southwest 
breeze. 
Leominster throws a corker for a right angle bird, and one lltais toi 
pull in lively, or he will find he is behind it, and hear the moin'ra- 
lul call, "Lost," and in this hole most of the misses were made 
yesterday. 
This was the third of a series of six shoots, and is for the toiaJ 
number of birds broken. The standing previous to this shcuat was 
F"itchburg 412, Leominster 410, Gardner 400. Now, at lb* cit«l of 
the first half of the series, Fitchburg has broken 617^ Gwiii»cr 601. 
Leominster 601. 
The next shoot of the series will be held in Fi.t,eto«*-tf, Monday, 
.\ug. 5. 
Fitchburg Gun Club. 
Tavlor 11101111111101101100111011111110101111111111111111—42 
Rob 0111]11011111011000111111101100H«J111|1100110110011— 35 
Converse . . .11101111100110110011110110101111.1011111111111111] ]— 
W ilder 01111111111110111011011101111111^1.1:111111111111111— 4.5 
Cutler ,.11]l]]111011111111111101UlioUlll]i.i111011111ll001— ^.i— 205 
Gardner Gun Club. 
Lenoir 01011101110nil011110H01W1101111ieilll01111111]0--3S 
Paine 00101101110011110111010111111101111110111111110111—38 
■Knight OlllllllllllOlWllOlllinilllllOlllllllllOlomil-44 
Leland lOOllllHllllllWlllHOOllllllllllllOOllllllllllOl— 41 
Sr. w I n nil CilHOUllimUllOOmOlOlOlOin 1 1 1 111111 01111—40—201 
Leominster Gun Club. 
Kice UlllllllimOlOl llOlllOOOlHlllllllllllOllOlllHl— 42 
Burbank . . . .llllllOlOlOllOlllllllllOllllOOlOOlllllllllHOlllll-^ 
Andrews . . . ,011110111111110111110101010100101111111 11000101110— 35 
Powers lOOOnillOOOllllUllOllllOUOlOUllOKllUllllllllOOl— 3# 
Farrar HlHlllOllOlllOllllllllllllOllOOlOllll 11111101001— 40f-l'yi; 
I. O. CONVERSBi. 
In a contest for the championship of Mercer county,. N. July 
10. between Messrs. C. A. Comp, of Yardville, and G. N. "Thomas, 
of Trenton, the former won by a score of 44 to 40. Each shot at 
50 targets. The rnatch was shot on the grounds of the Trenton 
Shooting Association. Dr. Thomas broke the extractor of his 
gun in the sweeps before the match took place, which hampered 
hini ci great deal. He was accorded the privilege of postponing 
the race on that account, but rather than disappoint the large 
gathering he ganiolv shot it out to a finish. 
■6 
Mr. J. O. Jordan, of 24 Brown street, Springfield Mass., in- 
forms us that he will forward programme of an all-day tournament 
to be held on July 24. The programme provides a total of 300 
targets, with ^Vf.Za entrance.. 
