Im an LEO and building a Combat Oriented Patrol Rifle. Due to its role I want it light, maneuverable (I work in an urban environment) and reliable, especially for a two way range.
Due to departmental restrictions it can be no shorter then 16 inches. Therefore Im building the gun around a 14.5 inch Daniel Defense barrel with a permently pinned and welded Adams Arms VDI Manimal Extended Flash Hider, which would allow me to remove the gas block without cutting the barrel. I like there lightweight mid lentgh profile due to weight. They also have a slightly heavier government profile 14.5 in carbine. The handguard would extended up until the muzzle device starts, so it would not have an effect on which gas system I use.
I have been reading a lot on Dwell time, and read a couple forums posts. My question is when would one choose carbine vs. Mid lentgh and vice versa for a 14.5, and how would that choice affect what BCG and Buffer to use (Im leaning towards BCM M16 Bolt Carrier Group). I am not planning to use an adjustable gas block or adjustable BCG. The goal is for an accuarte, reliable gun that shoots smooth for quick follow up shots.
Duty rounds will be .223 but I want it to run 5.56 with no problems. Some people on forums report issues with the 5.56 and 14.5 mid lentgh, however they didnt specify what BCG/Buffer they were using which may effect it. They weapon needs to be reliable, and two malfunctions on a qualification course would not allow it to be approved.