make one
I made a strip for one of my rifles by using a strip of black elastic. The elastic is about 1.5" wide. The strip is a tad shorter in length than the barrel from muzzle to where it joins the receiver. I fashioned two sewn loops on either end of the strip. There I attached two loops of para cord. The end at the receiver got tied/looped around the base of of the scope ring. The cord at the end at the muzzle was tied in a loop, just big enough to slip over the muzzle and stop. The elastic was mildly stretched, and thus llightly tensioned out over the barrel. There is minor contact out where the loop passes around the muzzle.
Check your zero with the strip in place, it could change POI or group size (didn't in my rifle).
Mirage strips are pretty common on match rifles with long strings of fire. "ready made and home made types abound.
