Shooting without Valve spring and retainer.
Last night I was busy doing some chrony work when I heard a ting sound that I hadn’t heard before. I picked the rifle up off the rest and something was loose inside the bottle-it could only be the retainer and valve spring.
I then went ahead and emptied the tank but still shooting over the chrony. Velocitied had picked quite abit nd the rifle was quieter.
Once empty I removed the valve and refitted the retainer and spring. This morning I was thinking about removing the retainer and spring altogether.
Now my question, has anyone done this and is it a good idea?
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Viewing 9 replies - 1 through 9 (of 9 total)
If you fill your gun with the Airforce fitting you must have a valve spring to close it.
I run my vulture sans Sri g as it has a fill fitting . Have no issues with it provided opening is controlled limited to less than 0.100″
Thanx for all the input guys, I should start testing within the next week or 2. Will keep you upto date.
Nick,
The one thing i can offer up on is, test your guns thoroughly both ways.
From one AirForce to the next, they vary too damned much. In other words, if you get good results, someone else may not. Simply cause of Airforces QC and wide spread tolerances. While the gun will work without a return spring, the consistency goes outta the window. But its all on what you want outta your gun
Give it a go, and let us know
I would go with the testing and if it works consistant, and alittle more power, why not.
Thanx Dyotat, the idea of running the tank without retainer and spring is to have unrestricted airflow-but if you’re getting 170fpe with a light tension on the valve spring then I’ll rather go that route.
Anyone else with some info that might help?
I have never tried running a valve without a spring or retainer. My .25 valve that has made 170 fpe has a very light spring.
.308 has to have a stiff spring or tank dump happens on heavier slugs.
I haven’t tried a light spring in the .257 yet but should be able to run a lot lighter because I’m only shooting 73 gr instead of the 171 the .308 can shoot.
Thanx Mrnewbie, I did put loctite on the retainer but then removed it as I wasn’t sure if it would diesel/detonate under pressure. When emptying the tank, it didn’t dump. When I had around 20bar left I unscrewed the tank and gently push the valve against the carpet to get the last bit of air out.
I’ve had a new one piece stem and tophat made with the 3 ports on the step as suggested by Dyotat and now I’m just waiting for my .22 barrel to arrive-then my 100fpe .22 Condor project will be back on track.
I’m hoping to hear some more opinions from the experienced guys.
Dayotat and the power mongers are all better equipped to give a definate answer on this one..but I’ll throw in my 2 cents..
Yes, I recall a thread where removing the return spring was an option. The thought being the pressure inside the tank was enough to close the valve.
As I recall this did work, however there was a point that the tank air did not close the valve up..and the fun and excitement of a tank dump would ensue.
If it was me..I would put it back together with only a few turns of the retainer brass nut with locktite..or put in a weaker spring.
Dayotat would be the best one to ask..
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I run my vulture sans Sri g as it has a fill fitting . Have no issues with it provided opening is controlled limited to less than 0.100″
Voltar, you’ve brought up a little problem that I’ve been thinking about for some time. I have an idea but not sure if it’ll work until I start playing with it. I’m still waiting for my .22 barrel, once that’s arrived I can see if it will work. I’ll keep you guys updated.