Refreshing my pellet gun

I found a place in remote Ohio that specializes in refreshing old Benjamin and Sheridan air rifles. Mine is a Sheridan Blue Streak
Mine was a tack driver for MANY years then about 2 years ago it started shooting irradicably. I recently bought a new Gamo to replace it but I am not satisfied with it so far so I was motivated to refurbish the old girl. Hopefully they do just that. They advertise all new seals, Im sure a good barrel clean/check then chronograph and return. I shipped it today.
Sad thing is the shipping and packing material coupled with the repair are more than its worth but it should last the rest of my life even though Im sure I wont be able to pump it that long!

Was it as .20 cal? I had one and it began to do strange things so I bought a .20 cal [5mm] cleaning rod with a jag and a brush. I found a small cork at the Ace place that fit in the breech end of the barrel tight, then I filled the barrel with lead removing solvent that I used a years back on a muzzy. It sat for two days with that elixer in the pipe, then I dumped it and gave the barrel a thorough workout with the brush. A couple patches, some oil on the seals and right back in business.

learned the diesel trick back then too. The .20 cal pellets had a nice hollow on the back side so I’d put a drop of oil in that cavity, then seat the pellet. The heat from the compressed air would ignite the oil when the gun was fired. I’d get about 200 fps more velocity. Chronoed it. Those pellets when they hit anything with hair or feathers were unreal.

I have half a box of the old Sheridan .20 pellets which aren’t made anymore. They may last forever if I don’t target practice much. I should have cleaned the barrel better and will if it doesn’t come back fixed. Thanks for the tip. At least I’ll have all new seals!