Krupp 75mm mountain gun M. 1904

Bulgarian designation :

75-мм скорострелно планинско оръдие “Круп”

Krupp denomination :

7,5 cm Gebirgs-Kanone M. 05

Calibre :

75mm L/14

Weight of the barrel :

105 kg

Weight of the breech-block :

19.5 kg

Weight of the carriage :

280 kg

Weight in action :

411 kg

Barrel length :

1.050 m

Rifling

length :

746.5 mm

twist :

increasing, from 1 in 45 to 1 in 25 calibres

Barrel grooves

number :

28

depth :

0.75 mm

width :

5.92 mm

Height of the line of fire :

685 mm

Shield

thickness :

3 mm

weight :

24.6 kg

height :

0.4 m

width :

0.2 m

Cartridge

weight :

755 g

shelled :

6.017 kg

charge :

162 g of Rottweil smokeless powder

Shell

weight :

5.1 kg – charge : 105 g Picric acid

fuze :

time – weight : 130 g

max. range :

5000 m

Shrapnel

weight :

5.1 kg – charge : 100 g of black powder

200 bullets x 11 g

fuze :

time and percussion – weight : 290 g

max. range :

4500 m

Muzzle velocity :

330 m/s

Remaining velocity :

206 m/s at 4500 m with shrapnel

199 m/s at 5000 m with H.E. shell

Angle of descent :

at 100 m – 0° 18’

at 500 m – 1° 31’

at 1000 m – 3° 12’

at 1500 m – 5° 11’

at 2000 m – 7° 32’

at 2500 m – 10° 09’

at 3000 m – 13° 09’

at 3500 m – 16° 38’

at 4000 m – 20° 42’

at 5000 m – 32° 42’

Elevation :

+ 15° / - 10° (with axle in low position)

+ 25° / - 10° (with axle in high position)

Traversing angle :

4°

Height of wheels :

800 mm

Track :

740 mm

Length of the axis :

970 mm

Transport :

4 loads: 1 – barrel and elevating gears = 164.6 kg ; 1 - shield and fore-carriage = 156 kg; 1 – cradle, sledge and recoil gears = 161 kg; 1 – trail, wheels and shaft = 157.6 kg

Without the pack saddles the loads weighted 110 – 120 kg

ammunition load : 16 rounds = 145.7 kg

battery load : spare parts and accessories = 104.8 kg

Ammunition :

128 shells (16 boxes, with 8 rounds each, each ammunition pack animal carrying 2 boxes - each ammunition box with 8 rounds weights 52.3 kg)

Remarks :

Quick firing mountain gun with hydro-spring recoil system, single-motion wedge breech mechanism, traverse on pivot. It was equipped with the Krupp mountain sight, but it had not the independent line of sight. It could fire the same ammunition as the Schneider mountain gun, but it had to employ different firing table, since the ballistic features were different.

In 1904 Bulgarian Army bought 9 six-guns batteries armed with Krupp mountain gun M. 1905 with 512 shells per gun. The delivery ended in October 1905. In 1911 2 more guns were bought in order to transform the existing 9 six-guns batteries into 14 four-guns batteries.

Drawings of 75 mm Krupp mountain gun