So I've always had some interest in the Young bolt carrier and was considering buying one - however, in the features, Young makes a point of saying "M16 Hammer Ramp."  I wasn't able to Google precisely what that meant.  The uppers and barrels I've got right now (or rather, am waiting on...) are M4 ramps.  I was wondering if the M16 hammer ramp means it's angled for chambering with rifle feed ramps, or if it's compatible either way?  Thanks much for clearing this up.

SBR7 looks like he has what you are looking for http://www.ar15.com/forums/topic.html?b=3&f=15&t=385344

Thanks - I guess I was a little confused - so the hammer ramp is where the hammer from the trigger group would contact or pass-through the carrier to impact the firing pin?

it looks like its where the bolt carrier resets the hammer...or puts it back in battery

+1.

Doesn't have a thing to do w/the feed ramps on the barrel.

Colt, in one of their politically correct moments, decided to cut away the rear end of the underside on the carrier, and notch the hammer, so that if someone tried to make the ARs fire full auto, the hammer would catch on the exposed collar of the firing pin and tie up the piece. This was way back in the 1960s.

The rest of the industry slavishly followed Colt, even though the Feds had never required the makers to do this. In more recent years, both Colt and the aftermarket have started going back to originasl profile carriers, w/the back of the firing pin covered, and unnotched hammers; which gives a smoother action and a bit more reliability

thanks for the info

That makes more sense.  Since I hadn't heard the term I was originally thinking it was something face-side.  Didn't take in the term as a whole.  Appreciate the responses!