Different m4 track types questions.

The_Chieftain: He does. Basically there are two basic track types. The 18" track with the external guide horns, and the 23" track (HVSS) with the center guides.The very original track was just a simple flat rubber block, which gave limited grip and had to be rotated after a while to wear on the far side. Then they decided that was inefficient, and made one with double-thick rubber on the road-touching side.Still, though that gave good wear and pretty fair grip on roads, offroad it was still poor, so they developed a 'tread' or chevron to give  a bit of bite. This eliminated the need to carry additional grousers, such as you may see on an M10's hull side (or on an early vehicle, turret rear).There was also a track with steel chevron which used less rubber, which was a critical material.