What muzzle device?
You'll have plenty of room with a 13.4
Yeah that feels like it will be super tight but that's what I'm going for.
I might as well put the build list on here.
Barrel: Criterion 13.9" Midlength Core Series
Muzzle Device:Yankee QD Flash Hider
Hand guard:Midwest Industries 13.375" M-lok
Gas Block:Superlative Arms .625 adjustable gas block
Upper:Aero Precision
BCG: BCM (although I would consider others of similar quality)
CH: BCM
This might be overkill but I'm also thinking about pinning the gas block. (I sort of overkill everything)