the japanese soon worked on various techniques to improve the effectiveness of their guns. they developed a staggered firing technique to create a continuous rain of bullets on the enemy. they also developed larger caliber barrels and ammunition to increase lethality. protective boxes in lacquerware were invented to fit over the firing mechanism so it could still fire while it was raining, as were systems to accurately fire weapons at night by keeping fixed angles thanks to measured strings. another development would be the "hayago", a bamboo cartridge used to facilitate faster reloading. a hollow tube open on the both ends, the "hayago" contained gun powder, wadding, and a bullet. upon tearing open the tube's paper seal at the bottom, a soldier could quickly use it to pour the necessary powder into his weapon before placing over the barrel and using his rammer to load both wadding and bullet into the barrel at the same time. after use, the "hayago" could be kept for repacking or discarded.