Originally Posted By mm34b:
How many Colt barrel contours are there? More than these?
Original thin barrel style.
Later style of barrel that was tapered at the front sight to thicken the exposed barrel.
Same thickness the entire length through, rather than just the exposed section.
M203 launcher cuts or steps.
No expert, but from memory...........
M4 (I guess what you label as stepped) M4 is light under HG, .650 (IIRC) at FSB, stepped for M203, and stepped up forward that.
There is also a Heavy version of the M4 that is heavy under the HG
There is a stainless 24" used and may have its own unique profile and maybe even a Bull barrel
Check w/ Ekie, or AR15barrels.com (Randall Rausch?)