I bought one to throw on a gun with a muzzle mount suppressor, just because I felt that if the can is always there, the gun will always be overgassed - why not.
Without an overgassing problem I would stay away, your rifle might not function with it. (If you can afford to try it out, go ahead.
Stay away from McFarland one piece gas rings though as they will definitely not be functioning the rifle with a fatboy. I had that problem once and it was tough to diagnose as I had so many different products working together on the same rifle. (that's why it's also nice to add one product to the "STOCK" weapon at a time, so if the gun stops running properly you know exactly what the problem is.