BCM upper clarification

[g-men10455]

Please forgive my ignorance but can someone explain to me what's the difference the standard & the BFH BCM uppers? What does the BFH stands for?
Thanks in advance for the replies.

[Tecstar1]

BFH=Barrel Hammer forged. Standard isn't hammer forged.

[Iraqgunz]

http://www.bravocompanyusa.com/BCM-11-5-BFH-Carbine-Upper-Receiver-Daniel-p/bcm-urg-11-bfh-ddl7.htm