Lose the softpoints.
You are going to want FMJ's, or something where the front of the bullet is more closed up.
As to feedramp mods, here is what M4 ramps look like:
www.ar15barrels.com/gfx/feedramps.jpg
Should be no problem to cut the ramps deeper and blend into the receiver.
No need to eliminate the bottom locking lugs, the rounds feed off of the two feed lips on the mag, alternating from the left and right.
Randall
www.ar15barrels.com