I ordered one, I'll post some pics when I get it.
For what it's worth, every other reference to these barrels, from my Google Fu, from other sellers ponits to these barrels having rifles ramps. Engage was sure that these had M4 ramps, I called twice to confirm. From my completely unofficial research, I came to the conclusion, that there was a batch of replacement barrels (hence the cage code vs. FNMI, ordered by the USMC that was either returned or was an over run and was surplussed. I've found very simalar barrels that have sold on GB, Armslist, and other sites, non of which have m4 feed ramps. I'm not calling out Engage that they they don't know the difference between rifle and m4 ext, but I took the chance and ordered one anyway. Either way, you'll all know when i do.
Quik