Viper, SAC, Davidson, PMA Tool, Brownells, Mechforce, 21st Century, Farrelld...???

I am using the Viper, I cut up some 1/8 inch x 2 inch wide belt leather to fit. One top one bottom. It protects the barrel and allows me to really squeeze the barrel. Done two m24s and a heavy varmit with no marks on the Cerocoat.
 
I'm using the Viper as well, for the money it's hard to beat. I just wrap the barrel with an index card and tighten it down good. The leather might work even better. You can spend a lot more money but I'm not really sure how much you gain unless you're using it everyday.
 
I'm using a PMA vice with a piece of target wrapped around the barrel for grip and protection. I've read people sometimes use drywall joint tape, (the dry type), to do similar purpose.