AR forearm hand position (grip )

[sabresbrs]

Why do I see alot of guys putting their hands extremely forward on their rifles when they are shooting. It looks as if they put their hand on the front post and lock it out or something. Any ideas? It looks very uncomfortable.

[kmrtnsn]

It is very stable, has greater mechanic advantage for pulling the weapon tightly to the shoulder, and it is faster moving from target to target.

[militarymoron]

discussed in detail in this thread:
http://www.m4carbine.net/showthread.php?t=79601