When I get my 15-22 I was thinking about getting one of the for it. Does anyone know the dia. of the barrel on a standard model?

Model 1 Sales: YHM Front Sights

That setup won't let you put a bayonet on, unless you cut the forearm back some. The barrel is smaller than 3/4 and bigger than 5/8. There is no information on that site except for how much the sight is. Found the info elsewhere. You will need to shim or bush the barrel for the tower to stay on. These gas blocks have a bore diameter of .750 inches.
The bayonet needs 5.125 minimum from the back of the pommel, where it seats on the mount, to the front of the muzzle ring on the guard.

Must be thinking about doing one of the terrible, but all to common, bayonet heists of a convience store. Nothing like a bayonet wielding bandito to get them to empty the safe, like fast.

Can't imagine one on a polymer gun. Don't u think that will look a little odd? Mixing across centuries. Anyone have pictures?

Bayonetes have polymer grips. I'm sure it's all about the look. Our cars don't need chrome, but it completes a particular look.

Well - well - I was thinking about getting a stainless 22LR blank and cut out a 20 inch barrel for it. I dont have everything in front of me, I know the block is .750 and I asked what was the dia. of the stock barrel was which I don't know. Plus will the barrel wrench fit on the .750 dia. barrel? I don't know what the dia. is on the stock barrel where the barrel nut goes. Just asking for some measurements Thanks. I know about the bayonet spacing needs, I was going to add it for something different. All in all I was going to make it look like and feel like a target model AR15. Just looking for a new project to do.