PROPOSED RUSSIAN FIELD GUN. 
385 
Number of Hits per cent, on a Target 6 ft. X 5 8/if. 
Guns. 
Dist 
ance. 
4-pr. 
V = 1004 f.s. 
9-pr. 
V= 1060 f.s. 
4<-pr. 
V= 1340 f.s. 
sagenes, 
500 
yds. 
1167 
52 
66 
87 
1000 
2833 
16 
18 
31 
1500 
3500 
3 
5 
8 
From these tables it appears that by increasing the initial velocity of 
the 4-pr. common shell to 1340 ft. per second, the trajectory is from 
10 per cent, to 19 per cent.—according to the distance—flatter than 
that of the 9-pr. (weight of shell filled, 24^ lbs.) fired at a velocity of 
1060 ft. per second, and 26 per cent, flatter than that of the 4-pr. 
common shell fired with an initial velocity of 1004 ft. per second. 
Further, .the probability of a hit on a vertical target at a distance of 
500 sagenes (1167 yds.) is in excess of that of the 9-pr. by 33 per 
cent, and of the ordinary 4-pr. by 67 per cent. 
Although at a range of 1500 sag&nes (3500 yds.) the probability of 
a hit with the 4-pr. common shell, with an initial velocity of 1340 ft. 
per second, exceeds considerably the probability of a hit with the 
service field guns, still that probability is so small that with the heavy 
4-pr. it would be wrong to open fire at such a distance excepting in 
rare cases. 
To form an idea of the gain in the probability of a hit, let it be 
agreed that the maximum distance at which we should open fire is 
that at which one-fourth of the shots would strike a target 6 ft. x 58 ft.; 
we shall then find that this distance with the present 4-pr. is 800 sagenes 
(1867 yds.), with the present 9-pr. 900 sagenes (2100 yds.), and with 
the heavy experimental 4-pr., with an initial velocity of 1340 ft. per 
second, it is 1100 sagenes (2567 yds.) 
In 1870, intelligence having been received of the experiments with 
a heavy steel 4-pr. by the Prussian artillery, a steel 4-pr. gun was 
designed in Russia to fire at an initial velocity of 1700 ft: per second. 
The length of the bore and the weight of the piece were approximately 
identical with those of the heavy bronze experimental gun; but in 
order that the gun should resist with safety the strain of firing a charge 
sufficient to give the projectile so high a velocity, it was hooped with 
steel rings at the breech. Furthermore to diminish the expansive 
action of the charge, it was decided to use large-grain powder (0‘25-in. 
to 0‘4-in.) of a density of 1*72. The experimental guns were made in 
the Obuchoff and Perm gun foundries. With a projectile weighing 
14 lbs. (12‘65 lbs. Eng.) inclusive of the lead-coating, and with a gun- 
charge of 5^ lbs. (4*69 lbs. Eng.)* of powder, the initial velocity was 
1703 ft. per second. With this charge, a pitch of rifling of 1 turn in 
* Relative charge = ^ nearly, 
