Ok. what are m4 feedramps exactly? Anyone have any pics to help a stupid guy out?

Thank you sir.

I should have just asked you first.[:)]

I was trying to take a picture of my ramps and I found out how hard that was-

whoever took those pictures had serious talent. Those ramps are very hard to photograph.

In case you don't have M4 feed ramps and want them, they are very easy to put in yourself. It only took me about 10 minutes with a small rat tail file, then a dab of Aluminum Black where the reciever was filed. I dare anyone without the aid of a serious magnifier to tell the difference between stock ramps... heck mine look better than those shown above as the cuts in the receiver line up perfectly with the cuts in the barrel extention. The key is keeping the file parallel with the orignal ramps so as to not change the angle, just make them deeper/wider, and to use light presure, getting even lighter as you get close.  

I bought a Colt 16" pencil barrel last year from J&Ts, one of the last ones they had, pre-ban, bayo lug, A2 front sight post, 1/9 twist still in the sealed Colt plastic. To my suprise, this barrel has the enlarged M4 feed ramps? Any ideas why?
Thanks
Mark

Except for my old SP-1, every Colt upper assembly I have has the "M4" cuts, even the ones that aren't marked M4.  Colt sometimes works in mysterious ways.  

Because they ran a large production run of those barrel extentions, there was no reason to throw them away when you can use them on any barrel.