Autotrigger Mag Pump

[Cristobal]

I've been thinking for a while about how to make a pump-mag with an autotrigger. The key to doing this would seem to be to find a mechanism that would interrupt the direct linkage that currently exists between the trigger and the sear. That way, when the trigger is pulled, it doesn't hold the sear "open" but allows the sear to toggle with the pump stroke. If the gun has been pumped, then it fires immediately upon a trigger pull. Otherwise, it waits and then trips the sear each time you pump.

So enough theory: I think I've got a way to do it. I've modified the following graphic to show how I think it would be done. It should be pretty self-explanatory, but I'll add a few notes:

-The telescoping trigger rod and spring combo make up the mechanism that allows the gun to operate with an autotrigger.
-The pump rod could reset the sear in any number of ways, but I've got another pic I'll post that shows how it might be done with a simple modification of the existing pump kits.

[Cristobal]

Here's my idea of a simple way to make the existing pump kit actuate the sear. Anyone with some pliers and a dremmel should be able to do it.

Basically the idea is to have the pump rod push the front of the sear up. By removing a small section of the body rail, the pump rod could be bent 90-degrees into the center of the rail so that it rests underneath the angled part at the front of the sear. When you pump, the rod will push back against this angle and push the sear up -- rather like the action between the autococker sear and trigger plate (only backwards, because in this case the angled surface moves up and down). Excess trigger rod could be cut off, or bent down at an angle to increase contact area with the sear (as shown in the pic).

A more elegant solution could probably be devised, such that the out-stroke of the pump toggled the sear, rather than the in-stroke (probably making for a smoother autotrigger), but this way is pretty simple and still ought to work.

Here's how it looks:

[cougar20th]

the only thing im not sure about is that the way the pump kit works is it pushed the bolt back.

with the rod pushing the sear there appears no way to push the bolt back and in not sure that the sear will do it because it slopes the wrong way.

[Cristobal]

Originally posted by cougar20th
the only thing im not sure about is that the way the pump kit works is it pushed the bolt back.

with the rod pushing the sear there appears no way to push the bolt back and in not sure that the sear will do it because it slopes the wrong way.

Sorry, should have made myself clear: the wave spring is not used.

The bolt is returned to its full rest position by the mainspring.

The only part of the existing pump kit that I'm suggesting to use is the pump assembly, simply because I think it could be modified fairly easily so that it "pumps" the sear instead of the bolt.

[Cristobal]

Time to revive this thread. I now know there's at least one thing I didn't consider when I came up with this idea: degassing the marker. I'm thinking that using a sear w/spring setup as above would result in the marker firing when degassed... which probably wouldn't be a good thing

So back to the drawing board. And maybe a move to the Workshop -- that'd be a better place for this than Deep Blue

[mh53eplt]

good idea though, if you know where I can buy a second pump rod for my marker I would like to play around with your idea too

[Jacko]

MAGMONKEY is selling pump rods in the dealers forum

[mh53eplt]

thanks for the info

[AkumA]

this thread is from last year, but anyone thinks it works or is doable?