Anybody ever tried to thread the barrel on an AR-15 using hand tools (no lathe)?
My Bushmaster carbine has the heavy barrel which, as I recall has a 3/4 inch OD.
Obviously, that would be hard to get down to 1/2"-28 thread.
I have seen this tool advertised that supposedly gets you started straight.
But you'd have to start with an OD close to 1/2 inch.