Pump mag question - Bolt spring?

[daemon512]

I'm used to other pumps, and non-blow-forward markers, where the entire pump stroke is recocking a spring. My question is, if the way a pump mag works is to prevent the bolt from returning fully to its back position, why is a wave spring used behind the bolt instead of simply removing the bolt-return spring in front of the bolt?

My thinking is, if that spring wasn't there, less air would be required to move the bolt forward, saving gas over semi-automatic. The only issue I could potentially see is if the sear would then have to rock into a semi-back position again in order to push the bolt back, opening the on/off slightly and allowing some gas to escape, but is that what happens or is that pure speculation?

[Smoothice]

If the bolt spring wasn't there then you would have to move the bolt inches instead of centimeters to recock it.

Basically the bolt would be all the way forward. And you would have to recock it all the way back. Which means the bolt would be to far forward for the pump rod to even be able to grab it.

Thats one of the great things about a mag pump. Your pump stroke can be extremely short.

Edit:I imagine you would quickly destroy both the body and bolt as well with the bolt slamming into the body every shot.

[daemon512]

Couldn't one sacrifice short pump stroke for an increase in air consistancy by cutting the bolt spring down to say 1/4 of its length then?

Sorry, I'm not trying to be difficult, I'm just used to pumps conserving air, and while one of the reasons I want to pump a mag is for the great stroke, I'm curious if I could do something for a time where I may need to be more air conservative.

[pinkanese]

part of the reason for leaving the bolt spring is so that the bolt will move back far enough to seal in the powertube, otherwise you would leak air down the barrel. Another problem is that the pump mag system is not designed for a long pump stroke The pump rod ramps up at the end to recock the bolt, it then returns to its forward position and drops out of the way of the bolt

Hypothetically you could make a new pump rod and mill off the ramp in the rail and move the bolt the full inch or so by hand, providing you found a way to make the powertueb seal and not leak air down the barrel constantly But what is the point? it would still be an open bolt pump you aren't helping yourself either

[Smoothice]

part of the reason for leaving the bolt spring is so that the bolt will move back far enough to seal in the powertube,

Forgot about that. Thanks.

[daemon512]

I understand now, thank you!