Single Set vs. Double Set

[Cory Joe Stewart]

Hello everyone,

I have never built or shot a rifle with a Single Set Trigger.  Are there any particular details to be aware of with Single Set?  What was more common historically?

Cory Joe Stewart

[rich pierce]

Terminology can be confusing. Here’s my terminology which may not be common.

Double action double set triggers have 2 triggers and the front trigger will fire the gun when the triggers are not set. Early rifles sometimes had these and higher end later rifles as well.

Single action double set triggers have 2 triggers and they must be set to fire the gun. Common in the percussion period.

Single set trigger has one trigger and must be pressed forward to set it and fire the gun. Some may be able to fire the gun unset. Some fly away from the finger when they release. They are rare on long guns and sometimes found on target pistols. Only advantage I can see is they fit a guard with a small bow.

Please correct my terminology with the more common terms as needed.

[Cory Joe Stewart]

ok. yes. So I am asking about Single Action Double triggers.  Thank you for helping me clarify.

Cory Joe

[Daryl]

Same here, although I thought the terminolgy was:
double set, double throw.
double set, single throw.
single set.
I thought all single set triggers worked both ways, set and unset.

[rich pierce]

I’ve handled original late percussion rifles with no half cock notch and set triggers where the front trigger will not fire the gun. I can’t use such guns anywhere but at the range. I like to bring a percussion rifle to full cock then set the trigger. Just my preference. I don’t want the trigger set and gun at full cock and then settling my grip.

[Cory Joe Stewart]

I’ve handled original late percussion rifles with no half cock notch and set triggers where the front trigger will not fire the gun. I can’t use such guns anywhere but at the range. I like to bring a percussion rifle to full cock then set the trigger. Just my preference. I don’t want the trigger set and gun at full cock and then settling my grip.

So the trigger has to be set to fully engage the lock?

Cory Joe

[Daryl]

The double set trigger, single throw triggers on my first longrifle, I didn't like, so I switched them out for a set of double set, double throw triggers I bought from Track. They worked perfectly.
Didn't like the lock either, so I switched that out for a Dickert lock from Track. Amazingly fast lock.

[Ross Dillion]

If the trigger is set up correctly on a double lever, single phase set trigger it will work normally. Cock the rifle, set the trigger, and fire. I have a couple of rifles with double throw set triggers and never use them without setting the trigger.

[RAT]

I use basically the same terminology as Rich... except I use the word "acting" instead of "action"... so it doesn't get confused with revolver actions.

A properly set up lock and trigger will allow you to cock the lock with the trigger unset. This is safest. Basically it means there is sufficient "backlash" with the rear trigger so it doesn't actually touch the sear when unset... but it will move up enough under spring tension to trip the sear when the set trigger is fired. The rear trigger will actually move up far enough that it will no longer be in contact with the trigger's mainspring. The spring should be strong enough that the rear trigger "flies" up away from the spring and knocks into the sear with enough force to move the sear up and fire the lock.

If you have to set the triggers to cock the lock there is insufficient play and the rear trigger will be in constant contact... and exerting constant upward pressure on the sear. If you try to cock the lock with the trigger unset, the hammer/cock won't hold position because the sear might not be engaging the tumbler notches sufficiently.

There was a photo and description of a single set trigger on page 3 of this recent forum thread.
https://americanlongrifles.org/forum/index.php?topic=74930.50

[Seth Isaacson]

I actually just wrote up an explanation of some of this terminology recently after receiving some questions:
https://www.rockislandauction.com/riac-blog/trigger-mechanism

I've definitely seen a fair number of double phase and single phase double set triggers on original American muzzleloading rifles.

I’ve handled original late percussion rifles with no half cock notch and set triggers where the front trigger will not fire the gun. I can’t use such guns anywhere but at the range. I like to bring a percussion rifle to full cock then set the trigger. Just my preference. I don’t want the trigger set and gun at full cock and then settling my grip.

Some are setup that way, and some just need adjustments to work without setting the trigger. My original percussion rifle wouldn't cock without setting the trigger several years ago. Then Art Fleener tinkered with it and got it to work without setting the trigger. I shot it for a while without any issue other than it having a very light set trigger, but after stirrup/link on the mainspring broke and I got the lock repaired, the rifle is back to only working if the triggers are set first. The trigger mechanism on the rifle is a double set, double phase meant to be able to shoot without setting the trigger. It just needs more work to get it right again which I'll eventually get done. I've handled plenty of originals that all that was needed was the tension adjustment screw to be loosened up a bit for them to work without setting the trigger, but some seem to have been built with the intention that the trigger always be set first, especially the later ones that only have a full-cock notch.

[Ross Dillion]

Most times it’s a simple matter of wood shrinkage and mounting screws over-tightened. I’ve fixed several rifles with this affliction by shimming under the trigger plate with wood from a popsicle stick.

[Bob Roller]

Terminology can be confusing. Here’s my terminology which may not be common.

Double action double set triggers have 2 triggers and the front trigger will fire the gun when the triggers are not set. Early rifles sometimes had these and higher end later rifles as well.

Single action double set triggers have 2 triggers and they must be set to fire the gun. Common in the percussion period.

Single set trigger has one trigger and must be pressed forward to set it and fire the gun. Some may be able to fire the gun unset. Some fly away from the finger when they release. They are rare on long guns and sometimes found on target pistols. Only advantage I can see is they fit a guard with a small bow.

Please correct my terminology with the more common terms as needed.

Your terminology is fine,Your description is spot on.I have made styles of all of these triggers and most double set that can fire the gun off the front trigger or when set.High quality single set triggers are not cheap and I made some for a German customer in the early 1980's.
Bob Roller

[Dphariss]

This is a great SS trigger.

[Bob Roller]

This is a great SS trigger.

VERY similar to the ones I made for the German years ago.He said most of these were made by watchmakers
in the French speaking part of Switzerland.Der Franzosicherruckstecher he called them.He made target pistols for a hobby.Forty years earlier he was a combat fighter pilot with an FW190 in the Luftwaffe.Now deceased.
Bob Roller

[Tacksman45]

Terminology can be confusing. Here’s my terminology which may not be common.

Double action double set triggers have 2 triggers and the front trigger will fire the gun when the triggers are not set. Early rifles sometimes had these and higher end later rifles as well.

Single action double set triggers have 2 triggers and they must be set to fire the gun. Common in the percussion period.

Single set trigger has one trigger and must be pressed forward to set it and fire the gun. Some may be able to fire the gun unset. Some fly away from the finger when they release. They are rare on long guns and sometimes found on target pistols. Only advantage I can see is they fit a guard with a small bow.

Please correct my terminology with the more common terms as needed.

Were single set triggers ever used on pre-revolutionary American longrifles?

[D. Taylor Sapergia]

I can't answer that question, but I have one on my Virginia Mark Silver rifle...love it.

[Dphariss]

Terminology can be confusing. Here’s my terminology which may not be common.

Double action double set triggers have 2 triggers and the front trigger will fire the gun when the triggers are not set. Early rifles sometimes had these and higher end later rifles as well.

Single action double set triggers have 2 triggers and they must be set to fire the gun. Common in the percussion period.

Single set trigger has one trigger and must be pressed forward to set it and fire the gun. Some may be able to fire the gun unset. Some fly away from the finger when they release. They are rare on long guns and sometimes found on target pistols. Only advantage I can see is they fit a guard with a small bow.

Please correct my terminology with the more common terms as needed.

Were single set triggers ever used on pre-revolutionary American longrifles?

There is rifle #81 in RCA vol 1 that appears to have a set trigger adjustment screw.
Then #77. Found these in about 45 seconds of looking.
But we have to wonder what the screw is for if not for a SS trigger, but the writer does not enlighten us.