DIY Auto-Trigger

[eclecticdialect]

I'm looking for a little insight on the AT's theory of operation. If anyone can help me out OR point me in the direction of someone who has done this before, I would greatly appreciate it.

[russc]

They usually go into a a hole that would be used by a safety. Think about if you had your trigger lightly depressed, and you forced it forward by pushing your safety in. Same idea.

By using a rotating cam shape inside the old safety hole, you can wedge the trigger back into a "safe" position. If it's locked safe when your pump arm is back, and allows the trigger to pull when it's forward, you don't release the hammer until your bolt has closed all the way.

[eclecticdialect]

They usually go into a a hole that would be used by a safety. Think about if you had your trigger lightly depressed, and you forced it forward by pushing your safety in. Same idea.

By using a rotating cam shape inside the old safety hole, you can wedge the trigger back into a "safe" position. If it's locked safe when your pump arm is back, and allows the trigger to pull when it's forward, you don't release the hammer until your bolt has closed all the way.

Ah!... So typically, the trigger plate travels back and forth while AT'ing? I've never actually fired an AT Sniper, so please excuse my ignorance... So, if the pivot point on the cam were it connects to the lever arm is adjustable, it doesn't really matter where the tapped hole on the pump arm is positioned, correct?

[Whee McGee]

From my understanding you would want the hole located where you can achieve two situations on each end of travel.

• Hammer cocked, trigger in "safe" position not activating sear.
• Hammer uncocked, trigger in "fire" position activating sear.

It is possible to drill the hole in a location where you don't give the AT enough travel to achieve both situations.

[eclecticdialect]

From my understanding you would want the hole located where you can achieve two situations on each end of travel.

• Hammer cocked, trigger in "safe" position not activating sear.
• Hammer uncocked, trigger in "fire" position activating sear.

It is possible to drill the hole in a location where you don't give the AT enough travel to achieve both situations.

That makes sense.

[Super69ur]

Yes. The trigger is moving while auto-triggering in a sniper. The cam is D shaped, with the flat section allowing the trigger to move all the way back. As the cam rotated, (Pumping the gun) it forces the trigger plate forward, allowing the sear to travel up and stay up until the pump handle travels all the way forward.