Silver solder would hold up. Regular 60/40 solder will probably deform. My .02
Elroy, when I had the rifle opened up with the compression chamber in place, that is when I adjusted the pump arm. I made sure it butt up to the end of the compression chamber and then backed it off less than 1/16. More like 1/32. ...I do seem to have a slight cam over.
Quote from: Pellet Fun on October 24, 2021, 01:59:48 PMElroy, when I had the rifle opened up with the compression chamber in place, that is when I adjusted the pump arm. I made sure it butt up to the end of the compression chamber and then backed it off less than 1/16. More like 1/32. ...I do seem to have a slight cam over.Thanks Dan. Your numbers are what I was expecting on mine. I'll check the cam over and length again. It's gotta be something I'm missing on the pump assembly. I may add another drop or two of oil while I'm at it.Elroy, it is a head scratcher.Try adjusting the rod longer so you have definite cam over. I chronied one of my 101s with a rubber pump cup earlier today and it was at 595 @8 pumps and 656 @10 pumps with 14.3 cphp. I attached a picture of where I can feel the piston bump the valve right before it cams over.
I have a Crosman 120 that was more or less a parts gun I turned over to a well known, now retired airgunsmith for rebuild/reseal. Upon examination he told me the gun was not capable of being resealed to full functionality because the pump tube brass was worn internally and showing signs of being out of round. I asked him to do it anyway, and he did. The gun had similar performance as yours. 20 or so pumps would get it in the 500's. Not to bum you out, but nothing lasts forever.
Gary, If there is wear in the tube or even a little out of round, I wonder if one of MAC1's flat top pistions seals with an o-ring would address the problem snce it is an o-ring and not a cup. I used one of these Flat Top seals on a S&W Model 77A and it bought the rifle back to life and did improve performance considerably. Here is a link to the Mac1 Piston Seal: http://www.mac1airgunshop.com/flat-head-piston-for-early-crosmans-p/mflhereki.htm