I have a M-15 Mig gun on a Millermatic 130 that I think needs the liner replaced because it has started having feed issues. The problem I have is when I picked up a new liner that was recommended by my local Miller repair depot it is not the same liner. My liner is a push in friction fit at the machine end of the gun and all the Miller ones that are spec'ed for my gun have a threaded flange on the machine end of the gun. The gun is original to the machine and I have never changed the liner. The people at the repair depot say all Miller liners screw in but I have no threads to screw the new liner into. Any suggestions would be appreciated.