420 
NEW AUSTRIAN 6-IN. BRONZE-STEEL GUN. 
With No. 1 gun this powder gave the following velocities and 
maximum pressures:— 
Charge. V.* Max. pressure, 
lbs. f.s. tons per sq. in. 
(6) . (371-0) . (1106) 
13- 2 . 1217-2 7-25 
(6i) . (389-2) . (1324) 
14- 3 . 1276-2 8-70 
(6f) . (399-6) .. (1415) 
14-8 . 1309-1 9-30 
(7) . (409-3) . (1507) 
15-4 . 1343-0 . 9-90 
(71) . (418-6) (1658) 
15- 9 . 1372-4 10-85 
(7|) . (427-3) (1682) 
16- 5 . 1400-9 11-05 
(7f) . (436-8) (1780) 
17- 0 . 1432-4 11-70 
(8) . (444-3) (1887) 
17-6 . 1457-0 12-40 
With No. 2 gun a charge of (8 k ) 17*6 lbs. of this powder gave a 
velocity of (445*4) 1460 f.s.,* with a maximum pressure of (1997) 
13*1 tons per square inch. 
A normal charge of 17°61bs. of this powder was consequently fixed 
upon. 
Further experiments were now carried out, in order to determine the 
respective range and accuracy of the two guns, and to decide upon the 
means of rotation to be adopted for the projectiles. These latter were 
2*8 calibres in length, and had been found to give greater range and 
penetration than those of 2*5 calibres. 
The shell for No. 1 gun were furnished (as already mentioned) with 
four copper rings, as in the case of those of the field guns of 1875 
those for No. 2 gun were provided with two copper rings (20 mm ) 
0*787 in. in breadth, and of the shape shown in the diagrams below. 
Fig. 2 shows the forward ring, the exterior diameter of which is 
such that it will penetrate (0*l mm ) 0*39 in. into the grooves of the gun, 
but not into those of the shot-chamber. The rear or rotating ring 
(Fig. 1) acts, however, in the shot-chamber ; its exterior diameter 
being greater by (0*l mm ) 0*39 in. than that of the gun, measured from 
the bottom of the grooves. 
Fig. 1. 
Fig. 2. 
The table below gives a comparison of the results of the first trials 
of the two guns with those of the Krupp 15 cm steel gun, tried in 1874, 
and the long Austrian cast-iron ringed 15 cm gun already mentioned. 
* At about 50 yds. from the muzzle. 
f Vide “Proceedings, B.A. Institution,” Vol. X., No. 1, p. 10. 
