Double- and Single-Set Triggers - Adjustment and Safety - by Dick Trenk


When improperly adjusted, a strong enough shock can cause the cocked hammer to be released and fire the gun. When properly adjusted, Pedersoli set triggers will not release when subjected to a strong shock. Read the instructions below in order to make adjustment correctly.

WARNING: Before making any adjustment make certain the gun is unloaded.

Double set trigger adjustments
(Sharps type rifles only)

REAR TRIGGER

1. Turn screw located behind the rear trigger, inwards until hammer will stay cocked without having the rear trigger “set” (clicked.)
2. If this screw is adjusted inwards too much, the hammer will not fall when the front trigger is pulled strongly.
3. If the screw is not set inwards enough, the hammer will fail to remain in full cock position.
4. The screw must be turned inwards until the hammer will remain in full cock without first setting the rear trigger.
5. When adjusting the screw, move screw in 1/4 to 1/2 turn increments and recheck results before making another adjustment.

FRONT TRIGGER

1. The front trigger will release the hammer even if the rear trigger has not been “set.”
2. With the rear trigger “not set” the front trigger pressure required to release the hammer will be much stronger than when the rear trigger has been “set.”
3. The front trigger adjustment screw located between the two triggers changes the amount of movement or travel which the front trigger must make before the hammer is released.
4. Turning this screw inwards will reduce the trigger travel and turning the screw outwards will increase the trigger travel required to release the cocked hammer.
5. If adjusted inward too much, it will not “hold” the setting against the rear trigger notch inside the action.
6. Proper adjustment should produce a very small front trigger movement with only a light pressure required to release the hammer.

Double set trigger adjustments
(Rolling Block type rifles only)

1. The single adjustment screw is turned inwards until the REAR trigger will not “set” when pressed firmly backwards.
2.  Turn the screw outwards until the REAR trigger will “just stay set”. In this position the front trigger will release the hammer with very little pressure applied on the front trigger and this is considered to be too light and dangerous.
3. Unscrew the screw “at least” one half more turn. This will make the front trigger have a little more resistance and be a safe setting.
4. If you prefer even more front trigger resistance then unscrew the screw an additional amount until you arrive at a satisfactory setting.
5. Perform the 5 safety tests listed below, to assure a safe adjustment has been made.

SAFETY TESTING THE ADJUSTMENT

If the front trigger has been set with a very short and light engagement it is possible that a strong shock or vibration might cause it to let the cocked hammer fall unexpectedly resulting in a discharge of the gun.

To prevent such an accidental discharge perform the following safety test.

1. Insert a fired cartridge case so the firing pin will have the dead primer to fall against and avoid damage to the firing pin.
2. Set the rear trigger properly, and then full cock the hammer.
3.On a Sharps rifle lower the breech lever and slam it shut least 10 times. On a rolling block type rifle, slam the breech block closed in a similar strong manner at least 10 times.
4.Hold the gun vertically by the barrel and tap the butt stock fairly strongly on a suitable rubber or carpet pad to create a shock inside the gun.
5.The hammer should not be released by this strong shocking action. If the hammer remains fully cocked, your adjustments are normal and safe.

UNSETTING THE TRIGGER
(Sharps or Rolling Block types)

Sometimes it is necessary to “uncock” and unload the rifle after it has been prepared to shoot and the rear trigger has been “set.” This is done safely as follows.

1. Keep gun barrel pointed in a safe direction.
2. Firmly press and hold back the REAR trigger using as much pressure as it required to “set” it.
3. While holding the REAR trigger firmly back, press FRONT trigger backwards lightly.
4. This “unsets” the trigger system so the front trigger will not release the cocked hammer with it’s normal “light” pressure.
5. Remember, the hammer can still be released by the FRONT trigger if a strong pressure is applied to the FRONT trigger.
6. With the trigger system “unset” the breech can now be opened and the live cartridge removed.
7.  With an unloaded rifle, practice this “unsetting” procedure until you can do it safely.

SINGLE SET TRIGGER
(RIFLES AND PISTOLS)

1. A small adjustment screw is located behind the trigger blade .
2. Turning this screw inward will reduce the pressure required to release the cocked hammer.
3. Turning the screw outward will increase the pressure required to release the hammer.
4. The actual “setting” of the trigger is done by pressing the trigger blade forward until a  click” sound is heard or felt.
5. The screw has a slot head for a screwdriver and it also has a small drilled hole which allows a small pin to be used to rotate the screw.
6. You can adjust the trigger to any reasonable release pressure between light and heavy but regardless of your final setting, the gun must be tested as described previously to make certain shocks or bumps will not cause an unexpected firing of the gun.

UNSETTING THE SINGLE SET TRIGGER

Once the trigger has been “set” and the hammer cocked, the only way to unset the trigger is to carefully hold the hammer while at the same time pulling the trigger as though to fire the gun.

Once the hammer has been released it can be slowly lowered to the uncocked position.

This is a very dangerous procedure because if the hammer slips from your fingers a loaded gun could fire!

Never attempt to uncock a flintlock action without first removing all the powder from the pan or removing the percussion cap from that type of gun.

Additionally, with a flintlock, place the frizzen in the “open” position so the flint cannot strike the frizzen and make sparks.

Keep the gun pointed in a safe direction in case the hammer does slip and make some sparks.

Remember there is a powder charge inside the chamber and it could be ignited by even a few small sparks hitting the empty pan.

Note that guns with a single set trigger can be fired without first setting the trigger. With a cocked hammer simply pull the trigger more firmly and the hammer will be released.

TO PREVENT ACCIDENTS

If you allow others to shoot your pistol or rifle, we suggest letting them try the set trigger operation before allowing them to actually load the gun. The very light trigger pressure is a big surprise to many shooters who have not had previous experience with the single or double set trigger system. The hammer does not have to be cocked to allow this trigger practice. Just set the trigger and allow the new shooter to experience the light pressure required on the front trigger of the DST type or the single trigger of the SST type.

 © 2004 R.Trenk Sr.