The Box Mod is both a mandate and a breeze. Most of my 223AI's kiss the 75A-Max shy of 2.500" COAL,though my LTR punched out,do Linda Lovelace things greater than that dimension...but still feed/functions fine despite the smallest spacer of the fleet.
The 75 S2 will make quite a bit more pressure at a like powder charge and I tend to skin it .5gr or so. The A-Max is just oh sooooooooooooo svelte. The difference in speeds ain't huge,but you don't wanna swap 'em to/fro and like for like.
