austro hungarian wwi siege howitzer 305 mm

305 1911 action aiming armor armour artillery ascent austro barrel battle bevel bombing breechblockl cannon cogwheel compensator deep delayed devastation explosive fuse gear green grooves gun heavy helical howitzer hungarian impact large mechanism mouth museum mrser nobody offensive olive painted pattern penetrate piercing pointing pounding recoil rifling rivets shell siege siegegun skodawerke war weapon wwi koda