406 
MINUTES OF PROCEEDINGS OF 
the small improvement that some of the angles of the grooving were 
rounded off. The twist was uniform, one in 266 inches or 38 calibres, being 
nearly the same as the final twist of the Trench gun. The bore was not of 
the usual cylindrical form but very slightly tapered, the diameter at the 
chamber being 0°04 of an inch larger than at the muzzle. This peculiarity 
existed in several of Sir William Armstrong's earlier experimental guns, but 
has not been carried out in all of them. The object is to give more windage 
in the region in which fouling has the greatest tendency to impede loading. 
8. The projectiles provided for the trial were as follows 
100 hemispherical-headed solid shot weighing 110 lbs. for the shunt. 
100 hemispherical-headed solid shot weighing 100 lbs. for each gun. 
60 ogival-headed shells weighted up to 100 lbs. for each gun. 
All had a windage round the body of *08 in. when the shot were rammed 
home, but the taper in the bore of the shunt reduced this to *04 in. at the 
muzzle of that gun. 
The 100 shot weighing 110 lbs. were not fired in competition, but the 
results are recorded in Table II. Tables III. and IY. record the com¬ 
parative results of the 100 lbs. shot and shell practice, respectively; and 
Table YII. the comparative facility offered by the form of groove for rifling 
on each system. 
Table II. 
Practice with solid shot of 110 lbs. from the shunt gun, corresponding to 
the shot of the first delivery in Report 3575. 
Date. 
No. of 
rounds 
fired. 
Charge. 
Diameter 
of cart¬ 
ridge 6-5 
inch. 
3 § 
Time of 
flight 
corre- 
Ranges. 
Mean difference 
of range. 
Mean observed 
deflection. 
Mean reduced 
deflection. 
11 
o O 
O'o 
sponding 
to mean 
range. 
Min. 
Max. 
Mean. 
13* & 
lbs. 
T ~"| 
sec. 
yds. 
yds. 
yds. 
yds. 
yds. 
yds. 
14. 2. 65. 
10 
25 
2 14 
3*56 
1,339 
1,447 
1,399 
29-6 
6-8 
1-0 
in. 
14. 2. 65. 
30 
21*9 
6 8 
7*30 
2,440 
2,648 
2,578 
39-2 
26-0 
2-6 
// 
10 
n 
10 5 
13-00 
4,025 
4,197 
4,108 
54-0 
80-5 
8-6 
n 
3f 
„ 
2 0 
— 
— 
— 
— 
•— 
— 
— 
lbs. 
n 
10 
20 
2 15 
3-39 
1,266 
1,371 
1,315 
24-5 
6-6 
0-6 
in. 
n 
10 
19*4 
5 8 
7-02 
2,349 
2,491 
2,417 
32-7 
22-7 
1-9 
n 
10 
II 
10 5 
12-65 
3,827 
3,953 
3,900 
27-7 
72-1 
9-9 
n 
3f 
II 
2 0 
— 
— 
— 
— 
— 
— 
— 
lbs. 
n 
10 
12 
2 19 
3-01 
1,003 
1,063 
1,033 
16-4 
4-2 
0-8 
in. 
n 
10 
6-9 
5 10 
6-30 
1,965 
2,074 
2,034 
25-5 
19-9 
2-7 
a 
10 
n 
10 6 
11-48 
3,300 
3,409 
3,364 
29-8 
.53-9 
6-7 
n 
3f 
a 
2 0 
1 — 
— 
— 
— 
— 
— 
— 
* One round only was fired on the 13th. f Fired for initial velocity. 
