A trick demonstrated to me by a friend in New Mexico. (I use "N"'s and it
doesn't bother me, but he was putting a 259 on a piece of coax and managed
to amaze me.) You use a soldering gun, but with NO tip at all! He pushed the
gun sans tip into the ring where the holes for the solder to the braid are,
and pulled the trigger. In very little time, the I*I*R losses had the 259
hot enough to melt solder and he flowed it into the braid. Gets the heat
into the right place, Give it a try.

W4ZCB