Need advice regarding pistol trigger and triggerplate.

[Rolf]

This is a test/practice version of a trigger+ trigger plate  for a pair of pistols I'm making. The trigger is pined to a lug that soldered on to the front of the plate. The slot in the plate is 0.7" long. I'm trying to keep it as short as possible, so I fit a set screw behind the slot and still it all inside the triggergard I made.The large "hole" in the trigger is necessary to fit the trigger into the slot in the plate.





The length of the triggerbar is 1".  The trigger hinge will 3/8 from the lock sear.
When the trigger is pulled, the triggerbar pivots upwards and the sear moves toward the end of the trigger bar. How short can I safely make the the trigger bar? I want to make the bar as short as possible , so I can make the slot in the plate shorter and have more room for the set screw.

Best regards

Rolfkt

[Dale Halterman]

I'm a bit confused. What is the purpose of the set screw?

When ask about shortening the trigger bar, are you concerned about introducing creep into the trigger? Not sure what the safety issue is, as long as the trigger bar is long enough to stay in contact with the sear.

Dale H

[Rolf]

The set screw is a feature I saw in a book about English duelling pistols. It allows you eliminate trigger creep and put tension on the sear to lighten the trigger pull.

I'm worried that if the triggerbar is to short ,the sear will slipp off the bar when the trigger is pulled.

Best regards

Rolfkt

[Acer Saccharum]

Also I think your trigger plate will have to be curved to fit stock contour.

You won't know how long to leave the bar until you have the lock in place, and then the relation to the trigger can be established.

When the sear has released, it may over travel by 1 mm, no more.

[Acer Saccharum]

Rolfkt, the overtravel set screw will go where?

I don't understand yet.

[Rolf]

The trigger bar is longer than the slot in the plate.The set screw is placed rigth behind the end of the slot in the trigger plate.When you screw it upwards through the plate, it pushes the trigger upwards towards the sear.

I have not put the set screw in the plate jet, because it must be bent to the stock first. I have to finish inleting the lock to the test stock before I can do that.

Best regards

Rolfkt

[keweenaw]

Rolf,

It's not a good idea to use a set screw against the trigger bar as a means of reducing the engagement of the sear on the tumbler.  As the wood changes dimension with humidity the set screw will change your engagement which might render the pistol unsafe.  Your tumbler notch and sear nose should be shaped to give a minimal safe engagement and the weight of the pull adjusted by changing the angles on the sear nose and tumbler notch. The higher you can make the pivot notch for the trigger on the trigger bar lug, the lighter you'll be able to make your pull.  If your trigger bar is 1.0 - 1.5mm past the back end of the sear, there is no way it will ever underride the sear.  If you're concerned with keeping the trigger up against the sear, it's an easy matter to mount a little flat or round wire spring on the trigger plate to push up the trigger bar against the sear.

Tom

[Rich]

Another thing to consider is that the closer the pin (hinge) is to the sear, the lighter the trigger pull. Getting the pin up high also helps.

[Rolf]

It seems I should be able to reduce the length of the trigger bar to 0.7", without causing problems

Tom,
I understand your safety consurns. I've worried about the samething. That's why the trigger is not pined to the stock. It's pined to a lug soldered to the plate. Wood movement can not effect the position of the trigger and the set screw. Of course the whole lock could move in relation to the trigger assembly. I don't know if this is a likely problem.

Your idea on the flat spring on the trigger plate seems safer. Ill try it out.

Rich,
It's not possible to move the pin closer to the sear without the grip getting uncomfortably small. On a try stock, the best fit was when the pin was 5/8" from the sear (I've got big hands. I use xxxl surgical gloves). On the next practice plate i've increased the hight of the lug from 0.6" to 0.8". Will see if it helps.

Best regards

Rolfkt

[keweenaw]

Rolf,

Even though the trigger is pinned to the trigger plate the trigger plate will move up and down, ever so slightly with changes in the wood.  On the original dueling pistols the small screw you see, sometimes in front of the trigger, usually to the rear is the adjusting screw for the single set trigger.  I don't know of any commercially available ones that would work on your pistols.  There seems to be a very high regard among shooters for the Pedersoli set trigger they use on their LePage pistols but it is apparently no longer available as except on their pistols.  With your metal working skills you could build set triggers to use in those pistols.  I would be glad to take apart the one I have in an old German holster pistol, photograph and measure up the parts and post them if you wanted to try building your own.

As for just adding a spring to keep the trigger up against the sear bar, here's a link to one on some shotgun triggers to give you an idea of how it's done.

http://www.trackofthewolf.com/(S(auoebk45svewue45pb4jdar5))/categories/PARTDETAIL.ASPX?CATID=14&SUBID=156&STYLEID=969&PARTNUM=TR-LR-DBL

Tom

[smart dog]

Rolfkt,
How well your set screw works will also depend on the shape of the tumbler on your lock.  The position of the sear bar sometimes changes when the lock is at rest, halfcock, and full cock.  Your set screw may not be able to accommodate all of those changes. It might snug up the trigger at half cock but not allow the sear to engage at full cock.  If you adjust it to be snug at full cock, you have trouble with the the sear engaging properly at half cock.  Some locks are designed so that doesn't happen but you should look closely at how the sear bar moves as you cock your lock to be sure.

dave 

[Rich]

I was thinking of making a new trigger plate with a taller lug and setting the trigger a little further back in the trigger guard ( to get the pin closer to the sear).

[Acer Saccharum]

I sometimes use a feather spring to keep the trigger in contact with the sear. It is so light that it just holds the trigger against the sear, but never strong enough to trip the lock, even if the sear spring breaks.


I have seen set screws used in precision guns to limit the trigger travel AFTER the sear has let off.

[Rolf]

Tom,
Thanks for your offer. I'd love to try to make a pair of set triggers for the pistols.
I copying an original would be great.


Best regards

Rolfkt

[keweenaw]

Rolf,

I got the old pistol out yesterday.  I'll pull the trigger out sometime this week and take some photos and measurements.  I have to finish putting together a pistol lock I've been working on first but I'm almost done with that job, just need to finish making and fitting the sear spring.

Tom