Snap On MW120 MIG Welder

When the wire is "bird nesting " it can be a few things such as the cable liner which is a specific size for the wire is one as is the proper size contact tip.
Is the drive roller the right diameter for the wire? Is the wire rusty ? Is there to tight bends in the cable to the gun? The other issue is improper tension on the MIG wire spool
035 wire is to much for a 120 volt mig machine. There is not enough amperage and that could be a problem as well