Reply To: The Crosman Powermaster 760…Recapturing my youth !

Forums Springers, Pumpers, C02, & Replicas The Crosman Powermaster 760…Recapturing my youth ! Reply To: The Crosman Powermaster 760…Recapturing my youth !



Hello again unionrdr. 

I wanted to ask if you have a problem with a loss of air pressure at the breach end of any of your vintage 760's…the Power Masters when you pull the trigger. I've been trying to find a simple way to to stop the leak and I believe I've found one. I was curious if you have the problem and if so how you dealt with it. My 760 is a variant 3.

After I managed to get it sealed I gained 17 fps average over 10 shots with pellets. My son has a 1994 version of the Pump Master and what they did (as you likely know) is encase the breach bolt in rubber and that curtailed the pressure loss.

I sort of copied that method to successful ends. I put a piece of 3/32" ID soft rubber vacuum tube over the small portion of the brass bolt where the magnet is, then used a utility knife to slice the majority of the rubber from the OD of the tube. I then used my 6" power disk sander to reduce the remaining rubber tube to approximately the diameter of the brass bolt. The bolt slid into the breach and barrel quite snugly even with a bit of grease but it moves back and forth easily and there is absolutely no air loss now.

I pumped 10 times and triggered it…it sounded like a mouse sneezing. So I removed the bolt and cut about half the length of the tubing off (it was originally the length of the magnet portion) apparently allowing much more air to exit through the muzzle…nice😁.

I've been trying all sorts of ways to do this and finally lighted on this. I thought if you had thought about stopping the loss in your guns but hadn't this might help and/or you could pass it on to your huge following.

Thanks for giving a listen.

Bruce Jennings (BIZNAWICH)

  • This reply was modified 1 year ago by BIZNAWICH.