GTA

All Springer/NP/PCP Air Gun Discussion General => PCP/CO2/HPA Air Gun Gates "The Darkside" => Big Bore AirGun Gate => Topic started by: shortshell on February 21, 2022, 09:02:54 PM

Title: Continuing the saga of the .457 Texan barrel swap to .308
Post by: shortshell on February 21, 2022, 09:02:54 PM
I made a stainless steel shorter & lighter hammer from the stock hammer of 110gm  down to 90gm & no luck so then put in a 1.6mm dia. spring wire & tank dumps continued every time, so now to make a top hat with smaller holes & less than the standard 5 holes & try again. The tank pressures do not seem to to matter from 1,500 to my regulated 2,200,psi. I have even tried lighter cast slugs down to 100gn. Now back to the lathe while the scuba tank fills but not at the same time. Never leave a HP compressor unattended.
Title: Re: Continuing the saga of the .457 Texan barrel swap to .308
Post by: MJP on February 22, 2022, 10:43:19 AM
Smaller diameter tophat od in to the breech, and smaller od on the barrel that goes in to the breech.

That is the only way you get rid of the dump.

Marko
Title: Re: Continuing the saga of the .457 Texan barrel swap to .308
Post by: rsterne on February 22, 2022, 12:54:03 PM
He doesn't want to hear that, Marko....  ::) .... has already stated on another Forum he doesn't believe that to be the cause....

Bob
Title: Re: Continuing the saga of the .457 Texan barrel swap to .308
Post by: shortshell on February 22, 2022, 05:36:33 PM
 In answer to the above I had not dismantled the valve setup until yesterday. I decided to try the other ideas first. Now the top hat or a set of screw in restrictions the after the poppet (like the after market condor valve) is the only way to go or make a different valve. I will keep the .308 barrel in storage as the .457 is really the best thing for my needs. I had contacted Doug by email but he did not reply.  With this type of valve design I feel uses too much air but the straight inline air route is a good place to start with my experiments.