Carrying a M4 or an AK, Is a little crazy. Yes you have a higher round count by concealing might prove to be a challenge.
The 9c is only slightly larger than the Shield 9 (same for the 40c/Shield 40 I have all four guns). For a while I was bouncing between the Shield 40 and the 40c, I finally setteled on the 40c for its round count and size. UNTIL i recently bought the 9c which now is my EDC. THis offers me the Power, Magazine capacity and size that fits my needs. I feel the 9c/40c conceals/wears just as well as the Shield 9/40. Currently I use a TT Gunleather Hi Ride Pancake holster and a Single mag carrier. This is a great holster that conceals very very well and is extremely comfortable
Thanks
1SG