18" barrel for an upper build? 29oz and rifle gas system should be a smooth and sweet shooter when hooked up to an A5 buffer system… 15" or 16.?" NSR or the longest KMR at the time for an upper build! BCM BCG BCM upper receiver. TROY flip up sights if any at all. Scope it…
I had a very similar idea last week but ended up with the 16" mid length.Plan to throw a 1-4 on it
BufordTJustice built pretty much exactly what you’re describing. Check it out in his thread:
https://www.m4carbine.net/showthread.php?147067-A-lightweight-Mk12-off-shoot-concept-quot-The-handy-rifle-quot
Thank you.
Mods, lock or delete please.