mag pump questions

[720datsun]

Hey I picked up a pump mag recently and I had some questions. I remember reading somewhere about using a spacer kit to tune but I need more info on that. Right now when I pump it it burps/hisses a bit but pumps and shoots fine. Any ideas what that problem is? Also when it is cocked it seems to be leaking out the bolt a tiny bit. after I pull the trigger but not recock it there is no leak. Ideas? Btw it has all factory milled parts and body with a clasic valve with lvl7. Thanks in advance for your help. One more thing I have 3 differnt pump rods all have a differnt angle to them on the bolt side. Why?

[Muzikman]

My guess the rods are not factory AGD rods, that would explain the different angles.

The tuning with the spacer is basically to use the shortest spacer possible. With the pump mag you want bolt stick. The original kit came with a very short spacer, one that was not in the normal AGD spacer kit.

As for it leaking out the bolt when it is cocked, I would check the power tube oring.

[Thunder Bunny]

You don't want bolt stick, you should have a wave spring behind the bolt instead of the rubber bumper. The wave spring keeps the bolt from resetting fully, and all the pump handle does is push the bolt back a little bit so the sear resets.

[Southpaw]

you may need to "tune" the rod that resets the bolt by bending down so it will not rub on the bolt when in the forward position. This may be why you may have mulitiple angles on the end of the rods.

[Muzikman]

You don't want bolt stick, you should have a wave spring behind the bolt instead of the rubber bumper. The wave spring keeps the bolt from resetting fully, and all the pump handle does is push the bolt back a little bit so the sear resets.


Yes, you want the wave spring, but what it causes is bolt stick. That is the reason for the very short PT spacer.

[720datsun]

I have the wave spring in along with the black bumper. Does AGD still sell the short spacer?

[Geoff Call]

You can do what I did and just tune it up with a level 10 kit. Mine works perfect and always has with lvl 10, plus its good if I ever switch back to semi here and there. The trick to putting a level 10 on the pump mag is to use the smallest spring that comes with it, or even better use the stock classic mag spring. Do this so you don't have too much return force on the bolt causing it to reset on the sear. The wave spring is supposed to stop the bolt from returning, but is not a sure fire method and it takes a group effort from other parts of the marker. Then tune your carriers and shims around your need for PT spacing. I think mine is a 1 with 2 shims, I could be wrong. Yours would probably be different anyways. Good luck and if you have anymore questions feel free to PM me. I've put quite a few pump mags together so I've got a good handle on them:) You can see mine in the for sale section of AO.

Thanks,

Geoff Call

[Little_Ho]

Hi

I did not have any trouble with mine. I use no Spacer kit because the Classic Valve i use used a spring instead of a spacer. And i have no problem at all.

I do had to bend the Pump rod up a little bit because it was not catching the Bolt at all.

Little_Ho

[space_weazel_45]

the space is small.....about .17 i think, i was having the same problem so i got the correct measurement(.17 is a guess from memory) and took a regular spacer put it in a lathe and cut it down to size, fixed all my problems. this is all i can suggest. good luck.