Before feeding it into the line try this..

Take a common green scrubby pad (Scotch-brite) and cut it length-wise
to be a 1" strip then fold it over in 1" squares in a Z pattern like an
accordion in as many layers as you can make depending on the pads
length..

Put the new spool ON the mount then poke the wire through all the
layers of the pad THEN feed it into the guns hose..

This way if there is any crap or the starting of corrosion on the wire
it will be wiped off as your pulling the trigger...

It wont pull into the line hole at all (done it for years), But the
bends in the pad scratch the surface of the wire as its' moving into
the line to keep it clean...

Ever seen a spool that has sat for a winter turn all green?

Rob in NH aka:
http://www.PABlater.com
"sandblasting with low-pressure"