Threading FAL for muzzle brake

[CHM]

I am trying to install a 9/16 x 24 LH muzzle brake on this rifle. The OD is 0.591 inches. Do I need to turn down the muzzle before threading it? 9/16 is 0.5625 inches. It seems close, but I'm not sure. Any experience out there? Thanks!

 

[Sunray]

You need the right diameter for a 9/16-24 thread. 9/16-24 is a UNEF size.
Have a look here.
http://www.brownells.com/1/1/15534-...al-thread-alignment-tool-f-a-enterprises.html

 

[CHM]

Mission accomplished! I purchased the die and handle from Wholesale Tools online and ultimately the TAT from Midway. Everything worked like a charm. I did NOT need to turn the barrel down or anything and my flash hider threaded right on like a champ. I will use a drop of Loctite for insurance, but am pleased with the result. I would definitely not attempt this without the TAT unless you have a lathe and don't forget the cutting oil! I took my time and removed the cuttings every half turn or so and chased the threads when I was done.