Roy, same problem with those, they don't stay on in the brush, specially once the barrel gets wet, if they need to be taped on, why bother! Like I said, I've been at this for too many years, duct tape works best.

Charlie, if you read the link I posted at Handloads, you'll see that it doesn't hurt anything and doesn't affect accuracy. I press it on the end of the muzzle, then press it on around the end of the barrel, a 2" square of duct tape will do ya. I've used electrical tape too, but it's harder to get off and gets brittle when it's cold. The duct tape works best when warmed a bit before applying. A little WD40 will remove any adhesive residue left on the barrel after removing the tape.
Tim