de-volumize my valve??

[autumnsscope]

I am planning ato run a 12 gram bucket changed on my pumpmag, and have read of people de volumizing their valves so they run better on co2. Is this necessary? What does it do? And how do you do it?

[kwood]

Not to thread steal but would this also make a semi mag more efficient?

[BigEvil]

Not to thread steal but would this also make a semi mag more efficient?

Nope, you would suffer terrible drop off.


autumnsscope - RRFireblade was doing this a while back. I think he used a small ring that used to be part of a Smart Parts gun - which offered these rings in three sizes that allowed you to do the same thing.. I cant think of the name of the gun.. maybe the Epiphany?

**Edit - not the ones from the Epiphany, they are too long, unless he cut them down which is possible.

[FA22RaptorF22]

I don't see why you would De volumize.

I almost would suggest the opposite by having an expansion chamber for the co2

[Ando]

I don't see why you would De volumize.

I almost would suggest the opposite by having an expansion chamber for the co2

[FA22RaptorF22]

Let co2 expand? So you dont get liquid? No comprendo?

[Fred]

the idea is to reduce as much system volume as possible so you waste as little CO2 as you can... 12grams are good for maybe 20 rounds TOPS if you are conservative in your rate of fire.
(with a Mag valve, I've tuned Phantoms to get 40-50... gogo nelson!)

[BigEvil]

On Rudz's gun he was getting 6-8 shots per 12 gram.. after RRFireblade was done IIRC he gets 12ish. Nice improvement if you are running 12ies.

[Smoothice]

Let co2 expand? So you dont get liquid? No comprendo?

you'd get 10 shots or so with an expansion chamber. All the air in the expansion chamber would go unused.


You are dealing with a pump mag. pump mag = slow rate of fire. Which means you don't really have to worry as much about liquid.

If this was a semi on a 20 oz then you would be correct.

[Smoothice]

On Rudz's gun he was getting 6-8 shots per 12 gram.. after RRFireblade was done IIRC he gets 12ish. Nice improvement if you are running 12ies.

I get 10-12 shots with a regular valve on 12'ies. I think rudz is pushing 20!

[Ando]

Let co2 expand? So you dont get liquid? No comprendo?

[FA22RaptorF22]

you'd get 10 shots or so with an expansion chamber. All the air in the expansion chamber would go unused.


You are dealing with a pump mag. pump mag = slow rate of fire. Which means you don't really have to worry as much about liquid.

If this was a semi on a 20 oz then you would be correct.

Ahhh I understand. I forgot this is a pump.

[Smoothice]

Ando is correct.

Filling the powertube is where you need to do the work. Xvalves have threaded powertubes. Some automag valves do as well. Pre "classic's" I believe. And some, maybe all, emag valves. Not sure on rt valves. The newer "classic" and minimag valves are lazer welded from what I hear.

By filling the power tube you will have a much slower recharge rate. But for a pumpmag, who cares.

[Watcher]

the idea is to reduce as much system volume as possible so you waste as little CO2 as you can... 12grams are good for maybe 20 rounds TOPS if you are conservative in your rate of fire.
(with a Mag valve, I've tuned Phantoms to get 40-50... gogo nelson!)

50 on my Ghost, at least. gogo nelson!


Seriously? Getting 10-12 shots off of a 12gram is terrible! My friends stock A-5 even got 24 or so, I can't believe that a mag valve is that bad.


Not sure how reducing the powertube volume would have an effect, but I can understand reducing the dump-chamber size. Only thing is that if you reduce the volume too much then you'd need a higher pressure. That would also have a negative effect on the efficiency.


On the whole, I wouldn't think it is worth it if you can only max out around 20 shots. But if you really want to run a mag on 12ies, all the power to you

[BigEvil]

With the pump set up, you barely need any mainspring, so there is that much less force needed to overcome it. The spring has to be just short enough to almost return the bolt. You can still have adequate pressure in the dump chamber, you are just decreasing the volume of air in there. If you used the set up for semi it would drop off.