Automag Pump ?

[Gee Tee]

I think the thumb screw in bolt just keeps pump rod from dropping out. The velocity adjustment on current sterling's is through pump rod from front, but early ones used springs and shims - athough a drop in dialer kit was produced. Input pressure needs to be around 600psi on older guns or you'll have a nightmare getting velocity up. A medium pressure bottle should work ok, but 850psi output regs will hold poppet valve shut.

Nice splash on the mag - it will make a great looking pump

 

[Canon Fodder]

I know some people have drilled a hole through the bolt from the back and used a long screw to adjust the velocity on sterlings - its only going to drop it lower though.

 

[Dave427]

Thanks for the relies.
I have done some research and came across this image of the internals for my Sterling. If i replace the front and rear springs, do you think it will solve my velocity issue.

The screw that fits in the rear of the pump rod does i think keep it all together. Its only a short screw.
I have also done some research for the Automag pump. But everywhere i have tried, do pump kits for the Auto-cocker only. Does anyone know where i could source some parts for the Automag conversion ? I looked at Rainman as suggested and emailed him, but no reply yet

 

[Canon Fodder]

Make the main spring harder (by shimming it with washers or replacing it) to increase velocity.

 

[Everyinchtheanimal]

found this whilst researching y frames for mags, hope it helps?
http://haveblue.org/tech/automag/index.html

 

[Gee Tee]

Make the main spring harder (by shimming it with washers or replacing it) to increase velocity.

Or go softer on valve spring - but you are flogging a dead horse if input pressure is wrong. Dropping bottle pressure or using an inline reg is the way to go on older guns. My mate Steve runs a two stage air america system, set at around 600psi into gun and it runs perfectly on the old CO2 spring/shim combination

There are machinists (like Rainman) making pump mag kits, but they are usually limited / pre-order runs that sell out quickly. Keep an eye on Automag.org or post a wanted thread stateside. That's your best chance of picking up a secondhand kit. Expect to pay $150-200 + shipping - especially if it's an original AGD factory kit

 

[Canon Fodder]

Or go softer on valve spring - but you are flogging a dead horse if input pressure is wrong. Dropping bottle pressure or using an inline reg is the way to go on older guns. My mate Steve runs a two stage air america system, set at around 600psi into gun and it runs perfectly on the old CO2 spring/shim combination

True, not easy to get hold of a reg that can do 600psi on the cheap nowadays though. Even the new AP ones say they are set up for a 500 or 600 psi input on their website (I think, it's been a while since I looked).

 

[Gee Tee]

The 1st generation Guerilla air Myth regulator is preset at 600-650psi

I've run one on a 0.8L bottle for my pumps

http://www.amazon.com/Guerrilla-Air-Myth-Paintball-Regulator/dp/B002U585LY