Pin-on is the way to go. - Geissele Super Gas Stainless Steel Block w/SS Dowel Pin

This gas block is one of the few that has the ability to be pinned. You can screw gas blocks down all you want, but there is always the chance it will move. Once it is pinned, it isn’t moving. Yes it will cost you an extra $50 or so to have your barrel drilled and pinned by a professional, but it is money well spent and once done you will never need to give it a second thought. Great Geiselle quality, low profile so it fits under all the various floating handguards I have. Buy it, pin it, and you won’t regret it.