I'm with duxuk. If it goes in a couple of inches past the clamp, then it's not deformation near the clamp and my money would be on rust or crap further down the tube.
Get a bit of broom pole, evostick some 180 wet and dry round it and sand out the inside ad far as you need. Grease and hopefully Bob's your uncle.
Get a bit of broom pole, evostick some 180 wet and dry round it and sand out the inside ad far as you need. Grease and hopefully Bob's your uncle.