Do I need to install the crush washer with a Flash hider?
There are a few ways to install a flash suppressor. You can use a vise, but most people just use their hands. If you’re using a vise, clamp the barrel into the vise and then put the flash suppressor on and tighten it down.
If you’re using your hand, hold the barrel with one hand and use the other hand to put the flash suppressor on. You’ll want to twist it as you put it on to make sure it’s tight. Once it’s on, use a wrench to tighten it down – this will crush the washer so that it makes a good seal.
Make sure that you don’t overtighten the flash suppressor, as this can damage the barrel. Just snug it down tight and then give it an extra quarter turn to be sure.