stockclass pumpmag effecincy problems

[cougar20th]

what can i do to increase efficancy using 12 grams on my stockclass pumpmag. right now it only gets 6 or so good shots from a 12 gram after that the drop off. the 12 gram is vertical as a forgrip, microline to the valve, valve is a minimag valve but with a ans backhalf. valve works great in my other pumpmag running n2

[Lenny]

Try SS or macroline. Microline could be forcing the gun to shoot liquid CO2, or partial CO2. A larger airway would allow more room for the Co2 to expand.

Other than that, I'm not sure.

[PumpMag]

what can i do to increase efficancy using 12 grams on my stockclass pumpmag. right now it only gets 6 or so good shots from a 12 gram after that the drop off. the 12 gram is vertical as a forgrip, microline to the valve, valve is a minimag valve but with a ans backhalf. valve works great in my other pumpmag running n2
I tried a 12 gram twist changer before. But similar amount of shots. Velocity just drops after 6 or 7 trigger pulls. Keep in mind you need 800 psi to have decent shots. Your next bet would be to get a 3.5 tank. Small enough for your vertical setup.

[athomas]

What type of barrel are you using? Use a non-ported barrel about 11" long. Try reducing the velocity by 10fps.

[Lenny]

I completly forgot about the barrel/velocity thing. Are you using a Freak? If so, check out WWA's stubby-something front's. It'll keep your barrel to around 7" or so. That'll spike your velocity a bit and let you turn down your air supply.

-Lenny

[RedEyes]

try a reg. automag backhalf and not the ans one. you would want lil room as possible for air to stored. well i have a pump mag with am valve, microlined and with a 12g i get about ~20 shots using a jj barrel. with macroline i got 10-15 i think. you might just want to stick with a 3.4 or a 4(if you can find em) tank.

[cougar20th]

the barrel i use is a old j&j brass barrel. only the last inch or so is ported. im planning on swaping to a automag valve. with mathcing halves. hoping that will fix or help the problem. thinking back not that particular valve never liked co2. i guess ill just experiment some with differtn setups. i want to keep it on 12 grams since alot of the playing i tend to do is 12 gram only.

[DaFin]

Try to take out as much volume in the gun as you can. Granted it'll have an impact on cosistancy but it'll stretch the 12 gram. One Trick you can use is put a wire inside the line from the 12 gram to the valve.

I don't hold much hope tho, AIR valves are not designed with gas efficiency as the selling point. I used to play a lot of stock (12 gram, rock-n-cock) and what I noticed using a nelson based gun (Line SI Bushmaster) is that bigger valves and less volume was the ticket for air efficiency. By bigger valves I mean larger apatures in the power tube so that the air release is short and strong rather than longer and weaker. The valve I still have was custom made and on the old scale would easily be a 6+. On an AIR valve it'd be the power tube and teh stem inside the bolt that would constitute the apature. Maybe running a weaker bolt spring?

Volume. For the AIR valve the volume issue is going to be a problem, the design of an AIR valve requires a large chanber behind the power tube and in front of the on/off in order to function, maybe some gains can be made trimming that space down if at all possible.

For the really Old Schoolers that might read this, the maker of the valve was a guy named "Termite" that played in LA in the late 80's / early 90's.

Good luck,