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View Full Version : What does the size of the on/off pin do



phatty123
10-01-2007, 09:48 PM
I read at pbnation replacing the stock .750 with the emags .712 pin increases the reactivity of the trigger. Is this true. I am about to get a retro valve and I want as much reactivity as possible.

Thanks,
Barry

Smoothice
10-01-2007, 10:01 PM
from my understanding it makes for a shorter/lighter trigger pull. The .712 pin is IIRC meant for a emag. I have heard that if this pin is used in a regular classic valve it could go full auto.

I'm sure someone that knows what they are talking about is responding as I type :D

olinar
10-01-2007, 10:05 PM
I have heard this as well, just so happens i have an extra .712 pin lying around. I'm going to throw it in the valve and see what happens.

phatty123
10-01-2007, 10:20 PM
well could you get back with me with your results olinar.

Thanks,
Barry

Spider-TW
10-02-2007, 08:52 AM
I put a 0.712 pin in a classic valve, just to shorten the sear travel on my pneumag. It was starting to nibble on the rim of the bolt face, so I dropped in the next longer one, 0.728. It stopped the nibbling or at least slowed it way down.

Shimming the on/off or shortening the on/off pin means that the pin will not push up through the on/off oring as far, making it quicker to open up. At some point the on/off will open up too soon, before the sear can catch the bolt and the bolt will keep cycling. If you run it at the edge, the sear barely catches the lip of the bolt, making the trigger very fast and crisp, but the sear can start denting and chewing on the lip of the bolt. Eventually, the setup would go full auto when the sear can't hold the bolt anymore.

For a given amount of RT effect, shorter on/off pin travel in the oring means more kick back on the sear that doesn't get used up on the oring friction.

pump
10-02-2007, 02:58 PM
wouldn't the only way to get more reactivity is to up the psi into the valve or by making a new pin with a thicker head?

Tao
10-02-2007, 03:49 PM
Shorter the pin the more reactivity you will get until you get runaway full auto. All you really need is a .745 or .740 for a good reactive trigger. The emag pin will be too short. Either way you go it is not factory recommended, and will cause wear on your sear and bolt.

pump
10-02-2007, 05:01 PM
yeah i would rather have a perfect length pin and just up the psi into my gun

or make a pin like electrician

Piranti
10-03-2007, 05:14 PM
Why I have no clue and don't care, but i put an Emag on/off assembly in my XValve and boy was it reactive. And high rates of fire is not recommended by AGD due to wear on parts.