NEVER.. use side cutters when taking out or putting in contact tips on your mig torch ( especially when hot). When you grab the contact tip with side cutters and turn the tip, you are actually cutting into the tip and distorting the inside diameter hole which the wire feeds, causing the wire to drag inside the tip. hence causing feed problems and only gets worse when the tip gets hot. The wire can burn back and weld itself to the tip.

Happy Welding

Regards Ian