I placed a 3"x3/4"strip of soft weatherstip foam in a free-float barrel channel one time and it worked wonders.
At the range tinkering with a rifle, realized I forgot the cardboard shims I was going to use to play with forend pressure. Looked in my range box, hmm... foam earplugs, 8 or 10 of them under the barrel seemed to get rid of those occasional annoying flyers. That led me to full length bed the barrel with windshield urethane, it shot very well for a few years until It got a new barrel.
