leaking out the velocity screw on an classic automag

[nuggy43]

I have an automag 68 classic, and when I screw the tank into the gun and wait a little bit it starts to leak out the velocity screw. And then when i shoot the first shot is very loud and all the other shots after are normal.

[GA Devil]

have you chronoed it yet? Usually the simple thing is your velocity is too high when it leaks out the back. Or you may need a new reg piston. But try to chrono it first and see where it is at.

[Nobody077]

Usaly if it leaks out the back you are shooting in the 350+fps range. You need to crono your gun and see where your shooting, if it venting and your shooting less than 300fps you should try cleaning and oiling your gun, also look at the o-ring on your reg-piston, if the o-ring is good, your gun is clean and oiled and it still vents at under 300fps you may need to replace your regpiston

[GA Devil]

is there an echo in here? lol..jk

[Aegis]

has it always done this? Did you happen to install a level 10 kit recently?

[billybob_81067]

My minimag started leaking out the back when I insatalled a level 10 bolt, and the velocity was still well below 300 fps, so I unscrewed the velocity adjuster, pulled out the reg piston, and took out the brass pop off valve that's behind the velocity adjuster and reg piston.

I put the pop off valve in a rubber padded vise, took an allen wrench and unscrewed the top off of it, then I machined an aluminum spacer to fit inside the brass housing. Then I put the spacer in there and tightened up the top again. What this did was that it tightened up the spring pressure behind the pop off seat so that it will never vent off ever again! :D

[nuggy43]

The velocity is around 280 and still does it. The first shot is higher, in the 300+ fps range. But than after it is around 280.

[xen_100]

Originally posted by billybob_81067
My minimag started leaking out the back when I insatalled a level 10 bolt, and the velocity was still well below 300 fps, so I unscrewed the velocity adjuster, pulled out the reg piston, and took out the brass pop off valve that's behind the velocity adjuster and reg piston.

I put the pop off valve in a rubber padded vise, took an allen wrench and unscrewed the top off of it, then I machined an aluminum spacer to fit inside the brass housing. Then I put the spacer in there and tightened up the top again. What this did was that it tightened up the spring pressure behind the pop off seat so that it will never vent off ever again! :D

that is a good way to cause SERIOUS hot shooting gun that could injure someone......not to mention if the reg seat were to fail, you could send ALOT of pressure into the bolt and damage it. the blow-off vent is there for a reason! for $12 you can buy the correct regpiston.


to answer your question, there is only 3 reasons you will ever get leaks out of the back of the adjuster.

1) set to high......too high of a reg pressure will cause it to vent. (this can be a side effect of LX, since it runs at a high pressure) turn the velocty adjuster down and see if it goes away.

2) regpiston o-ring is bad. replace it. ( it is real easy to nick it when you put it in the gun, so be carefull)

3) bad reg seat. this will, again, cause a high pressure to be pressent in the regualted air side of the reg. replace the reg seat.

I suspect that 1 or 2 is your problem since it just started doing this.

[billybob_81067]

Originally posted by xen_100


that is a good way to cause SERIOUS hot shooting gun that could injure someone......not to mention if the reg seat were to fail, you could send ALOT of pressure into the bolt and damage it. the blow-off vent is there for a reason! for $12 you can buy the correct regpiston.


Guess what. If the gun is shooting hot you can, GASP! Turn it down! I just chrono every time before I play... it works wonders

[xen_100]

thats not the point. what if the reg seat starts to leak during a game? what if the regpiston hangs in the open position? both of these cases will result in full input pressure going to the bolt. if the vent was there, it would vent and you would know there is something wrong instead of popping some guy at 400+FPS!

[billybob_81067]

Originally posted by xen_100
thats not the point. what if the reg seat starts to leak during a game? what if the regpiston hangs in the open position? both of these cases will result in full input pressure going to the bolt. if the vent was there, it would vent and you would know there is something wrong instead of popping some guy at 400+FPS!

Never had either of those two things happen to me before and I've been using mags for quite a few years now... Besides I just play with a few of my buddies and we always turn our guns up until they draw blood anyways...

[athomas]

I would venture to say that the problem is a bad reg seat o-ring. The first shot would be hot and then every shot after would be fine until the gun sits for a while. As the reg seat leaks, it will leak high pressure to the front chamber. Once the pressure gets above the safety level it will vent out the back. If the leak is very small, then the vent out the back will also be very small.

[jterraw]

draw blood anyways...
no man, the reason why there is a 300fps limit is because any thing higher than that can break the bones in your fingers, the weakest link! something to do with physics-momentem. not to mention "your going to poke an eye out with that thing". really