the us army designed the t 13 beano grenade to

The U.S. Army designed the T-13 “beano” grenade to be similar in shape and weight to a baseball in order to leverage soldiers’ skills in the sport.  However, there were problems with the grenade’s fuze design and the weapon was eventually scrapped after WWII ended..– WTF Fun Facts

Source: https://medium.com/war-is-boring/american-hand-grenades-have-some-odd-connections-to-sports-d5196b64d0be