<P> Near the end of the war, both sides deployed more mobile light machine guns and submachine guns, such as the M1918 Browning Automatic Rifle and Bergmann MP 18 . </P> <P> Grenades proved to be effective weapons in the trenches but when the forces arrived their numbers and capabilities were inadequate . Hand grenades were used and improved throughout the war . Contact fuzes became less common, replaced by time fuzes . </P> <P> The British entered the war with the long - handled impact detonating "Grenade, Hand No 1". The No. 15 "Ball Grenade" partially overcame its inadequacies . British forces however mainly used an improvised hand explosive that was at times more difficult to use, yet still useful in battle . This was the Double Cylinder "jam tin" which consisted of a tin filled with dynamite or guncotton, packed round with scrap metal or stones . To ignite, at the top of the tin there was a Bickford safety fuse connecting the detonator, which was lit by either a cigar, or a second person . The "Mills bomb" (Grenade, Hand No. 5 ") was invented during the war and came into use in 1915 . Its improved fusing system killed more of the enemy and fewer of its users . The French meanwhile introduced the F1 defensive grenade . </P> <P> The major grenades used in the beginning by the German Army were the impact - detonating "discus" or "oyster shell" bomb and the Mod 1913 black powder kugelhandgranate with a friction - ignited time fuse . During the war Germany developed the much more effective Model 24 grenade or "potato masher" whose variants remained in use for decades . </P>

What were the main weapons used in ww1