BAT trigger timing

[tclaunch]

Someone please school me on the trigger timing. I have a new action and it came equipped with 2 trigger hangers, this option is an adjustable one I believe. It is part of the DS system. I could call Dwight, but thought this a great subject for discussion, Tim.

When I cock the bolt and it is in the raised position, the firing pin protrusion (rear) is at its greatest. The pin moves forward upon closing the bolt. Should there be no forward movement at all?

 

[lloydx2]

You should call Dwight and see how much firing pin fall is acceptable for that action. There are specs. I'm unfamiliar with that action. It sounds like your giving up some travel when closing the bolt. Maybe some will chime in that's been there and done that? Maybe?

 

[Viper8]

BAT makes two different hangers: 0-30 and 10-20. The hanger position '0' will position the trigger as much forward as possible. Installing it to '30' will move the trigger and firing pin back .030 inches from the normal '0' position.

Try all four settings. Start with the 0-30 because the 10-20 hanger will show smaller differences than the 0-30.

When you start closing the bolt handle slowly, the handle will stop after the cam,during the cam the firing pin will move quite a bit. At this 'halfway' point measure the distance from the back of the pin to back of the shroud. Then move the handle all the way down and measure again. You will notice it has moved slightly.
You should choose the setting which gives you the least firing pin movement when closing the bolt.

You will also notice how the handle is positioned when you hear the trigger reset click.

I only have a 0-30 hanger and it was easy to find the right setting. If I set it to 30 the firing pin spring would continue to compress when closing the bolt making it a bit stiff. Also the trigger would reset when the bolt moved back when the handle hit the cam. Using '0' the bolt will close easily and trigger will reset without having to touch the cam. The firing pin moves ever so slightly forward. According to my measurements, the 10-20 hanger set to '10' would be perfect for my action and trigger.

 

[tclaunch]

Great information, and thanks. The DS system must be that it includes both of the trigger hangers you mention. I had TM Stockworks bed the rifle, and I sent him the trigger. It arrived to me with the 0 in the front position. I have only been able to "eyeball" for any movement and would like to ask your method for measuring for movement. That would be the cats behind to be able to measure for movement, Tim

The rear indicator does move during the cam as you mention, but I cannot see any further movement, but thats hard to tell.

 

[jkohler]

tclaunch
Go have a look at benchrest central. Do a search on trigger timing and read what Jim Borden has to say about it. I was told you are looking for a smooth hand off to the sear and no cock on closing.

 

[tclaunch]

I will do that, I have solved the measurement technique. I have a Krieger barrel in the lathe, I will tear down the rifle to action and trigger, screw it on the barrel and use a dial indicator in the tailstock. This only has to be done once, so I`m gonna get it right from the get go.

 

[shinny]

jkohler,

Could you be more specifice where you saw the piece in BRC re: Jim Border/Trigger Timing.

Thanx

 

[JRS]

jkohler,

Could you be more specifice where you saw the piece in BRC re: Jim Border/Trigger Timing.

Thanx

Click on gunsmiths corner.

 

[jkohler]

Shinny
Jrs is right there is a hand full of thread on the subject in the gunsmiths corner. Or you can just do a search on the main site. Jim explanes it very well in a few threads on there.

Tclaunch the problem is if there is a firing pin travel problem of any size you more that likely cant fix it your self. The cocking peace would have to be altered more that likely to correct it. I set my last two actions up buy feel and they seam just fine. I just tyred the different hangers until they felt nice and smooth on the hand off from the cam to the top lever. I made shire there was no cock on the close and the forword movement was just from the cocking peace moving out of the detente notch. I did measure them after to see if they were in spec.