How do you tune a set trigger?

I have a new custom squirrel rifle with a small Siler lock, and I have not been satisfied with the set trigger (brand unknown). I could just take it back to the gun builder, but I want to learn how to do this stuff myself.

Adjusting the trigger set screw doesn't change the front trigger pull at all, which has been a source of frustration. I have adjusted the set screw from all the way in to all the way out, and everything in between, but that that doesn't change anything.

Now the hammer won't stay up in the cocked position. Again, adjusting the set screw doesn't fix the problem. Pulling the set trigger first also doesn't keep the hammer up.

The main spring and sear spring are new and in good shape. The lock is clean and lubricated. The lock functions properly when it is removed from the rifle. The sear properly and securely engages the tumbler at half cock and full cock.

I have looked at YouTube videos, and there's nothing useful there.

Do I just need to file down the set trigger plate where it contacts the sear?
Do I need to knock out the trigger mechanism and see what's going on?

I don't have the answer to the problem but don't touch anything with a file until you get the problem figured out.

Take some power out of the trigger main spring. Just back the screw on the spring a bit and try it. When you get it where you like it add locktite or nail polish.
I hope this helps.
W

There’s a sweet spot, with some patience you’ll find it!

Against my better judgement, I'm going to chime in. I am not knowledgeable about set triggers except for one thing that happened to me a couple of weeks ago. I was checking out a rifle I had recently acquired. The front trigger was difficult to pull. I tried too hard and then nothing worked. The cock would not engage and hold. I took the set triggers out of the rifle and began trying to see if I could figure out how they should work. Then I noticed a small wire laying on my workbench where I had removed the triggers. This small wire fit into two tiny holes on the trigger frame and the front trigger. After fiddling with it to discover how it fit and engaging it, the triggers worked as they should. Check the little wire spring to make sure it is in place.

With the lock out of the stock, look through the hole where the sear lever goes to ride over the trigger levers. Can you see trigger levers? The trigger levers should be below the sear lever. The first adjustment should be to lower the rear trigger lever to be below the sear lever. Generally, this will be the heavy mainspring. Once the real lever is adjusted to allow the sear lever and the nose of the sear to enter the notches in the tumbler, the other trigger adjustment screws can be turned for adjustment of the trigger pull. @Harry Marinakis's builder should have completed the adjustment of the triggers before delivery.

With the lock removed can the triggers be set? If the triggers can be set with the lock removed, can the set trigger tension be adjusted?

Review the adjustment instructions for the L&R set triggers. Most set triggers will be adjusted the same way.

Some important warnings to adhere to are the adjustments are to be made with the triggers unset.

https://lr-rpl.com/diagram-of-parts-trigger/

Grenadier1758 said:

With the lock out of the stock, look through the hole where the sear lever goes to ride over the trigger levers. Can you see trigger levers? The trigger levers should be below the sear lever. The first adjustment should be to lower the rear trigger lever to be below the sear lever. Generally, this will be the heavy mainspring. Once the real lever is adjusted to allow the sear lever and the nose of the sear to enter the notches in the tumbler, the other trigger adjustment screws can be turned for adjustment of the trigger pull. @Harry Marinakis's builder should have completed the adjustment of the triggers before delivery.

Click to expand...

So I file down the tip of the mainspring where it touches the tumbler to lower the set trigger plate so the sear can fit in the notches.

I've already driven 90 minutes to have builder tweak the set trigger. He fiddled with it for an hour, but the repair didn't last very long. I don't want to keep driving 90 minutes one way every time I need the set trigger adjusted.

Grenadier1758 said:

Review the adjustment instructions for the L&R set triggers. Most set triggers will be adjusted the same way.

https://lr-rpl.com/diagram-of-parts-trigger/

Click to expand...

These instructions don't work, my main spring doesn't have an adjustment screw.

There is a screw on the trigger plate that applies tension to the trigger lever. Turning that screw can raise or lower the trigger lever. No filing on the mainspring is required. At this point, all adjustments are to the triggers and the location of the trigger plate. There may be an adjustment to the sear spring tension in the lock. Need to see a picture of your triggers and the lock.

Grenadier1758 said:

There is a screw on the trigger plate that applies tension to the trigger lever. Turning that screw can raise or lower the trigger lever. No filing on the mainspring is required. At this point, all adjustments are to the triggers and the location of the trigger plate. There may be an adjustment to the sear spring tension in the lock. Need to see a picture of your triggers and the lock.

Click to expand...

That's the problem, turning the screw doesn't do anything.

Harry Marinakis said:

These instructions don't work, my main spring doesn't have an adjustment screw.

Click to expand...

Those L&R instructions are to the trigger plate. The triggers will need to be removed to adjust that trigger plate screw.

Grenadier1758 said:

Those L&R instructions are to the trigger plate. The triggers will need to be removed to adjust that trigger plate screw.

Click to expand...

Got it. I need to knock out the pin and remove the trigger.

Do you know what brand set triggers they are? Can you post a picture of the assembly?

@Harry Marinakis here is another description of the operation of double set triggers. This also shows the relationship of the trigger levers to the sear lever.

https://cdn.trackofthewolf.com/Pdfs/catalog/page_352.pdf

Harry Marinakis said:

That's the problem, turning the screw doesn't do anything.

Click to expand...

Perhaps the screw is too short?

Harry Marinakis said:

I have a new custom squirrel rifle with a small Siler lock, and I have not been satisfied with the set trigger (brand unknown). I could just take it back to the gun builder, but I want to learn how to do this stuff myself.

Adjusting the trigger set screw doesn't change the front trigger pull at all, which has been a source of frustration. I have adjusted the set screw from all the way in to all the way out, and everything in between, but that that doesn't change anything.

Now the hammer won't stay up in the cocked position. Again, adjusting the set screw doesn't fix the problem. Pulling the set trigger first also doesn't keep the hammer up.

The main spring and sear spring are new and in good shape. The lock is clean and lubricated. The lock functions properly when it is removed from the rifle. The sear properly and securely engages the tumbler at half cock and full cock.

I have looked at YouTube videos, and there's nothing useful there.

Do I just need to file down the set trigger plate where it contacts the sear?
Do I need to knock out the trigger mechanism and see what's going on?

Click to expand...

Harry, I am not being condescending but, do you understand how the set trigger works?

Can you take the triggers out of the gun trigger plate and all completely intact?

After taking them out, set the front and then release it with the rear trigger, do this until you understand how it works or why it doesn't, these things are really not that complicated but it is hard to diagnose without seeing pictures of your triggers.

@French Colonial, other than the T/C Patriot pistol, one sets the triggers with the rear trigger and releases the trigger levers with the front trigger for double lever double set triggers. With double lever triggers, the front trigger can release the sear from the full cock notch when the triggers are unset.

Grenadier1758 said:

@French Colonial, other than the T/C Patriot pistol, one sets the triggers with the rear trigger and releases the trigger levers with the front trigger for double lever double set triggers. With double lever triggers, the front trigger can release the sear from the full cock notch when the triggers are unset.

Click to expand...

Yes, correct, Had a brain f@rt.

So, I decided to remove the set trigger and see what was going on. But I am stuck.

Here is the trigger on my squirrel rifle. That set screw has never really changed the poundage of the front trigger when the set trigger is used.

When I use the rear set trigger, the front trigger is hard to pull regardless of how far in or how far out I move that screw. I screwed it all the way in, all the way out, and every position in between. No change in the front trigger poundage. I've got my .50 caliber set trigger dialed in perfectly, but set screw on this squirrel rifle has never really worked properly.

And now the hammer won't stay up when I try to cock it all the way back. I guess the sear is putting too much pressure on the trigger plate?



First I tried to remove the trigger guard. I knocked out the rear pin holding the rear section of the guard.

But the front section of the guard seems to be held in place by a staple or a pin that was bent over (white arrow). It does not go all the way through, so I can't knock it out from the other side. My .50 cal has two pins holding the guard in place, pins that I easily knocked out.

I can't grasp enough of this staple with pliers to pull it out unless I dig down into the wood to get a grip. Maybe I should try to pry up this staple with a tiny screw driver?



So It this point I am stuck with trying to fix the issue without removing the trigger. Here is what I got:

Both triggers pushed forward. This is the rear trigger plate, which I guess I need to file down so the sear isn't sitting on it? It looks like it's already been filed down some, I can see irregular file marks.



Triggers pulled