I've seen some pistols in the J M Davis gun museam that had that on the printed card beside them,
I've lived on a farm for most of my life, repaired a lot of busted barbed wire, when it breaks, you can't just tie it back together, you've got to make a loop on both broken ends by looping and tying it back over itself and then use either more barbed wire or just smooth wire to tie the two pieces back together, with a loop in the repair link, then you take a pair of fencing pliers or a stout stick and twist the middle portion to tighten the barb wire back up where a cow can't stick it's head through it. would be a lot easier with a gun barrel if you didn't have fence pliers or a stout stick close by.