Questions regarding singel phase dobbel set triggers for pistols 2.

[Rolf]

I’ve finished my first attempt at making a single phase double set trigger.

Got a few surprises along the way. I think this one works, but I won’t be using it in a pistol. There are a few details I want to change that I’d like to discuss.

Front trigger
I like triggers with wide shoes and was happy with the design until I tried to cut the slot for the front trigger.  Because of the wide shoe, the trigger had to mount the plate from the underside. To get it to fit I had to cut out a large piece of the trigger (trigger to the right fitted to trigger plate). As far as I can tell this does not have any adverse effects for function. Comments?



I also had to cut rather long slot to get the tail of the front trigger through the slot. This gives a large gap in front of the trigger. It’s ugly but seems to be a necessary trade off if I want a wide trigger shoe. Is there any functional reason I should not do this?
 


Main spring
How do I know if it is strong enough to trip the sear? Is there any way to test this without inletting it into a pistol? The main spring is made of 2.5mm (0.1”) thick spring steel. 6mm (0.24”) at the widest and tapers to 3mm( 0.118”) at the tip. Overall length about 2”. Heated to 775 Celsius for 15 minutes, oil quenched and tempered at 300 Celsius for ten minutes. When fired the main spring holds the trigger at a sharp angel.  I'll try mounting a back lash screw. How far back on the spring should it be?



When fitting a single phase double set trigger to a gun, the rear trigger blade, in fired position should not touch the sear.  Have I understood correctly?

Best regards
Rolf

[Don Getz]

Rolf......nice looking trigger.   You are correct, the rear trigger bar should not be touching the sear bar in the "fired"
position, it should have some play, or be rather loose.    The trigger bar should "slap" the sear bar and then relax away
from it.............Don

[Acer Saccharum]

Don is correct, Rolf. I have used a set screw under the trigger mainspring to relieve pressure on the rear trigger in the tripped position. This allows the tension to come off the sear, so you can cock the lock without having to set the trigger first. It also makes this position adjustable. This is also for safety, a concern so you don't get confused while cocking/loading/handling the pistol.

Your trigger mainspring looks strong enough from here.

If your lock geometry is correct, you won't need much of a tap to trip the lock.

Tom

[greybeard]

I have made a few trigger sets and I take a very scientific aproach for testing. I set the trigger. place a quarter on the top. touch it off and if the quarter jumps 12 1/2 inches in the air it will fire the gun. This test has never failed me yet. I also get the correct height by stoning the tip of the mainspring so rhe lock can be cocked with the triggers unset.
    Cheers   Bob


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