There are a few different ways to install a flash suppressor on a Ruger 10/22. You can either use a threaded barrel, which is the simplest and most common way to do it, or you can use a barrel band and sleeve.
If you’re using a threaded barrel, all you need to do is screw the flash suppressor onto the end of the barrel. Make sure that it’s tight so that it doesn’t come loose during firing.
If you’re using a barrel band and sleeve, first install the barrel band onto the barrel of the gun. Then slide the sleeve over the barrel and screw it in place. The sleeve should be tight against the barrel band to prevent any movement during firing. Finally, screw the flash suppressor onto the end of the sleeve.
Again, make sure that it’s tight so that it doesn’t come loose during firing.