Tuning Looking for fixture to prevent clipping o rings on Marauder

I recall seeing a fellow with a mom and pop air gun shop selling plastic jigs to fill in the holes in the main tube during valve instillation to prevent clipping o rings. I have tried getting in there and lightly sanding the edges but keep clipping the seals. Sometimes it leaks down immediately and sometimes I can go as long as four months before it leaks down. This has gotten to be such a pain I have rediscovered the joy of my Diana 34 springer while the Mrod sits gathering dust because Im tired of fooling with it. I had saved a link to the site but my hard drive crashed and now I cant find them on an internet search.
 
I had a similar issue with a Gauntlet. My fix was making a "fixture" as you describe out of a polymer clay that sets rigid once baked in the oven. This clay can be found at most hobby stores and is fairly cheap as it comes in small packages. "Sculpey" and "Fimo" are two well known brands. Just google "oven bake polymer clay". I made a two-piece deal and marked which went on the right and left of the barrel as to get the proper fit once baked. Hope this helps.
 
I found the right size of rubber stopper at ACE hardware for .80 cents and it worked perfectly on my Marauders

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Patrick


 
This looks interesting. You get the port filler, new valve, depinger and o rings. I have a depinger made out of some clear tubing and it works, but hey if if comes in the kit.... What would the new and improved valve do for a Gen 1 Marauder in .25. I am not a tuner but with the Bstaley O ring mod I was getting a flat curve with 16 shots of JSB domes at 840 +/- 10 fps before dropping off quickly. I was happy enough with that even if its not the best use of air bc I get free 4500 psi from a buddy at the local fire dept.



Archer Airguns Upgrade Kit for Benjamin Marauder air rifles. .25 caliber. Marauder. Benjamin. Mrod, M-rod, crossman, archer airguns.
 
Thanks much Brian. If Patrick's tip of using rubber stoppers doesn't work for me I will give the clay a try. There's a Hobby Lobby just down the road. Looking forward to getting the old pig up and running. Not related but I found a as new Hatsan Torpedo 155 underlever gas springer with less than a tin of pellets down the pipe for $175. Best new price is $300. Its a heavy beast that should be near 27 ft. lbs. in .22. Thinking some Haydes or Polymags will be tough on the local tomato stealing squirrels. Sweet, sweet revenge soon.