RRA new hammer?

[kdcgrohl]

The one in the POF is new as of last week, the one in the RRA is from early last year I think.
Why the change? Do you guys know if the one in the POF will function with a 416 upper?
http://i627.photobucket.com/albums/tt358/kdcgrohl/firearms/firearms37.jpg

[Warg]

See this thread (https://www.m4carbine.net/showthread.php?t=34614&highlight=notch+hammer).