Maxim-Nordenfelt 57mm gun

Bulgarian designation :57mm Максим Норденфелд оръдиеNordenfelt designation :6 –pr. Q.F. Caponnière GunCalibre :57mm L/48Weight of the barrel :195,6 kgWeight of the breech-block :19,6 kgWeight of the carriage :820 kgWeight of the field carriage :584 kgBarrel length :1.503 mLength of the bore :1.320 mRiflinglength :1.070 mtwist :decreasing, from 1 in 45 to 1 in 30 calibresBarrel groovesnumber :24depth :0.3048 mmwidth :1.88 mmCartridgelength :224 mmweight :684 gbattering charge :552 567 g of RLG² coarse-grained powderweight shelled :3.9 kgCast iron shelllength :210 mmweight :2.721 kg – charge : 75 g of gunpowderRing shelllength :218 mmweight :2.721 kg – charge : 85 g of gunpowderShrapnellength :208 mmweight :2.721 kg – charge : 30 g of gunpowder70 bullets x 15 gfuze :8’ time and percussion graduated up to 2500 mCase shotlength :3.712 kg – 196 bullets x 11 g / 17 gbattering charge :312 g of RLG² coarse-grained powderMuzzle velocity :440 m/sMax. range :2500 mElevation :+ 10° / - 2°Remarks :Light QF fortress gun. For service in caponnière the gun was mounted on a non-recoil carriage and elastic stand, that was fitted with small trucks, so that the gun could be removed easily from a position to another and readily fixed in its firing emplacement. In order to obtain greater mobility, it could be mounted on a light non-recoil field carriage.