Airforce breech question
I recently took a Talon in trade. It’s been converted to .357 using a Eldy big bore kit. It’s valve has been replaced with a Condor valve. When I received it, it had a piece of surgical tubing (1/2″ long) fitted over the top hat. It appears as though the tubing is providing an air seal by sealing off the top hat and breech at the instant the gun is fired. Without the tubing there’s noticeable blow by from the breech. I replaced the o-ring breech gasket but the breech still leaks when fired without that piece of tubing. Is there supposed to be another breech seal that would serve the same purpose as the tubing?
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:rofl: NICE….
I am sorry but My guess is that is Eldy’s solution to seal that breech. Those big bore kits of his from what I understand werent ultra sophisticated. You might even describe them as rather simplistic in design approach and budget.
I WILL MAKE DISCLAIMER THAT I NEVER HAVE HAD MY HANDS UP CLOSE AND PERSONAL ON ONE.
It does seem to me if I recall correctly that was one of his solutions to addressing the breech.
Problem is….
You have a bigger bore it requires a bigger barrel. A bigger barrel requires what? Again a bigger bore, in order to bridge the valve and the barrel. A bigger bored breech requires a bigger tophat and so on and so forth. The amount of fit and machining that goes into marrying a breech to a tophat and bridge the barrel too with its internal o-rings is a bit deceiving at first glance however this is rather sophisticated and tight tolerance to function properly especially at higher flow rates and pressures.
The surgjcal tubing surely is a low tech budget way of using a rather plain or stock tophat/valve stem to adapt to and bridge to the big bore. My guess is he drilled out the diameter of a stock breech and this tubing takes up the tolerance between the two components and seals in the air.
Hack or ingenuity?
You can make the call better than I………..
as you have one in your hands.
You might read up on the threads that mention blown up delrin breech. You can then determine if this is actually safe and sound way to seal and bridge with that kinda air pressure.
I have seen surgical tubing blown up like a balloon and have had a small piece full of model airplane fuel pop in my hand. It felt like i waa holding a lit firecracker as it exploded between fore finger and thumb….. Long story….(ok ok ok….. well I used the tubing as a high pressurized fuel bladder for hotrodded formula one type 1/2 a .051 airplanes and would fill them with a huge piston syringe and thats how I popped one in my hand. )
:2cents:
ELDY BIGBORE =NICE!
:rofl:
There is an oring that goes in the top hat between the top hat & valve stem. Look at my post AF Valve parts locations in General Chat. I don’t know if that is where your leak is, but it sounds like it is.
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I have been trying to find “Eldy’s big bore setup” but no luck on Google? Just dead ends.
Anyone have a working link?
Thanks, Rick