I came across a product you may want to try. I use a brownells vise and their collets (for lack of a better term), and have used a number of techniques shared here, and from other sources, always trying improve on avoiding damaging the bbl finish. I've used Steel and aluminum inserts along with tape, I've made custom Inserts with Deacon along with tape to protect the bbl finish. So far I've been lucky and only had one bbl spin in the clamps, fortunately it is was a throw away, the damage was of no consequence.
This past weekend I was going to remove a fairly new blued bbl I really didn't want to damage. looking around for a tape that had some good adhesive strength and as well some exterior grip I grabbed a role of tape used by hockey players. They use it on their hockey sticks. WOW, did that do the job! I didn't have to break the vise screws to get a good non-slip grip on the bbl. The was a real pleasure to work with, has excellent adhesive qualities, thickness, and a rough enough exterior to bond well inside the vise jaws.
Attached are a couple photos for your reference, you may want to give it a try.
This past weekend I was going to remove a fairly new blued bbl I really didn't want to damage. looking around for a tape that had some good adhesive strength and as well some exterior grip I grabbed a role of tape used by hockey players. They use it on their hockey sticks. WOW, did that do the job! I didn't have to break the vise screws to get a good non-slip grip on the bbl. The was a real pleasure to work with, has excellent adhesive qualities, thickness, and a rough enough exterior to bond well inside the vise jaws.
Attached are a couple photos for your reference, you may want to give it a try.