MTS 251si MIG Torch

HI Everyone, I have an issue with my MIG gun, when welding and the nozzle touches the steel I'm welding it causes my welder to seem like the nozzle caused to welder to ground out. It quits welding and for lack of a better term, sounds like it "choking out". Once I release the trigger and move it off of the work piece it welds fine until I touch it to what I'm welding. This came about when I was welding shock mounts on a frame and it was a very tight area so the nozzle would touch and immediately "ground" itself and stop welding. I was thinking maybe the nozzle is no longer insulated from the rest of the torch, not sure if that could be possible or if that's how it works, I'm a hobby welder lol. I was going to purchase a replacement nozzle but not sure what type I need. I bought this back in 2019 and looking at the current model on Everlast's site it shows a Series 36 MIG torch.

Thanks in advance for any input on this.

Most MIG gun nozzles are NOT insulated. These never were. You may need a smaller gun, like the 15 or 24.

The size isn't the problem. I should be able to touch the nozzle to the work piece. I took off the nozzle this evening and discovered some weld inside and I think that's touching the gas nozzle which when it touches the piece Im welding and ground out the gun. I need to get some new nozzles since I cant knock out the weld material.