F A Enterprises Ar-15 Barrel Thread Alignment Tool
The F A Enterprises Ar-15 Barrel Thread Alignment Tool is only $14.99 at Brownells these days, which seems to be a pretty good price.
Make sure that your die is located precisely before you start cutting metal. Stainless steel alignment tool fits in the barrel and keeps your die perfectly aligned when threading for flash suppressors and muzzle brakes. 1″ long shank inserts in the barrel to provide an accurate pilot point based on the bore position. 1/2″-28 threaded guide portion is 1/2″ long to give you plenty of room to get the die started correctly. Mfg: F A Enterprises SPECS: Stainless steel, in-the-white. 1 1/2″ (3.7cm) long, 1/2″-28 tpi. Fits AR-15 barrels with .224″ bore size.