I wanted to put on a scope, but did not want to remove front sight as it covers the Gas Port, so I contacted Brownells and they have an AR-15 Flat Top Scope mount for $39.95, some sights can be used w/scope mount as their is a Hole under the rings, it fits 1 Inch scopes. I have the S & W AR-15 Sport 5.56, 16 inch Bbl. #1551. It is called an AR-15 Flat Top Wide Mount.From Brownells Approx $46.00 including shipping. It looks real nice on the AR-15. The Flat top (cut out) goes toward the front to clear the collar. Hope this helps you Gary Bryant Dr.longshot