It has a "shaped charge" it burns it's way through armor, two models, M28= will penatrate 8 inches of armor. M31= 10 inches armor, 20 inches concrete , range 350 yrds,
Never saw one launched like that , we had a tall clipon rear sight cause it's a high angle weapon and it was launched with a M3 crimped round (special blank)
Also comes in smoke and illumination types
*note: this info is from 1962, but he's using a M-1 garand so i may be right.