Good info from SteakWarriors.
The Infantry’s Best Friend! 
Tanks win battles, but mechanized infantry wins the war! These transports hauled soldiers through mud, bullets, and artillery fire. The American M3 Half-track combined the steering of a truck with the off-road capability of tank tracks, carrying a squad of GIs into combat while providing heavy covering fire with a massive .50 Caliber M2 Browning machine gun. The German Sd.Kfz. 251 was the iconic ride of the Panzergrenadiers. Its sharply angled, sloped armor deflected small arms fire, allowing German troops to keep pace with the lightning-fast Panzer divisions during Blitzkrieg offensives. The British Universal Carrier (often called the Bren Gun Carrier) was tiny, fast, and fully tracked! It didn’t carry a full squad, but it was mass-produced to haul heavy weapons, ammunition, and small fireteams across impossibly rough terrain that wheeled trucks simply couldn’t handle. Riding in an open-topped metal box took guts!
