Pictorial: C4 Trigger Mechanism Maintenance

[Claudio]

Hi folks,

Here's a quick pictorial on how to maintain the C4 trigger mechanism.

Required tools: grease solvent, white lithium grease, 1 phillips and 1 slotted screwdriver, 1 brush.

Step 1: Remove the 4 screws that secure the trigger mechanism to the carbon body of the gun.

Step 2: Use the slotted screwdriver head to carefully dislodge the trigger mechanism case from the slot without damaging the carbon. The case will be snugly lodged in the slot as the tolerances is minimal. It helps to apply Silicone spray at the case edges to more easy dislodge it.

Step 3: Once the case is out, the first pin that must be removed is one on the top right of the case. This is the pin that hold the main component of the mechanism. Push the pin to remove it.

Step 4: After the top pin is out, use the slotted screwdriver to raise the main spring of the mechanism. The top component of the mechanism will slide right out.

Below is how the main mechanism component looked after 2 years of use... the slight corrosion comes from using spring steel South African shafts. I have since changed to a SS Mori shaft.

Below is how the shaft locks to the mechanism... notice the pivoting sear. Italian engineering at its finest and one of the reasons why the C4 trigger is so smooth.

Note: Before moving to the next step, take a good photo and make mental notes of how the trigger spring and titanium trigger are arranged against the main spring of the mechanism before removing them.

Step 5: Remove pin that holds the trigger and it's spring to the case. These components will slide right out. Then remove the main spring from the case by sliding the last pin.

Step 6: Clean all of the components with a brush and the a grease solvent. I used Liftoff Adhesive/Grease/Oily Stains Remover bought from Home Depot.

Below is the photo of the components already cleaned and ready for re-greasing and reassembly:

Here is a closer look at the polished main component. One word to describe how it feels in my hand... solid.

 

[Claudio]

Below is another photo where you see the in the wheel bearing that interacts with the trigger (by my thumb)... another reason why the mechanism is so smooth.

Below is a photo of the main trigger component lubed with a fresh coat of white Lithium grease (also bought from Home Depot):

Step 7: Reassemble the mechanism in reverse order. Main spring goes first, its pin, then trigger spring and trigger and their pin.

Then, lift the main spring again to slide the main mechanism back in place and attach its pin. Because it will be under tension from the main spring, you will need to wiggle it around until it is in the exact position for the last pin to to in.

Below is a photo of the reassembled mechanism. One important note, very little if any grease is needed around the springs of the mechanism. Too much grease will interfere with the trigger action and make it feel sluggish.

From here on all that is to lube the sides of the assembled case, slide it to the slot in the gun (some light tapping with the wood handle of a hammer may be needed) and screw it in place.

Cheers,
Claudio

 

[carbotti]

Hi folks,

Here's a quick pictorial on how to maintain the C4 trigger mechanism.

Required tools: grease solvent, white lithium grease, 1 phillips and 1 slotted screwdriver, 1 brush.

Step 1: Remove the 4 screws that secure the trigger mechanism to the carbon body of the gun.

Step 2: Use the slotted screwdriver head to carefully dislodge the trigger mechanism case from the slot without damaging the carbon. The case will be snugly lodged in the slot as the tolerances is minimal. It helps to apply Silicone spray at the case edges to more easy dislodge it.

Step 3: Once the case is out, the first pin that must be removed is one on the top right of the case. This is the pin that hold the main component of the mechanism. Push the pin to remove it.

Step 4: After the top pin is out, use the slotted screwdriver to raise the main spring of the mechanism. The top component of the mechanism will slide right out.

Below is how the main mechanism component looked after 2 years of use... the slight corrosion comes from using spring steel South African shafts. I have since changed to a SS Mori shaft.

Below is how the shaft locks to the mechanism... notice the pivoting sear. Italian engineering at its finest and one of the reasons why the C4 trigger is so smooth.

Note: Before moving to the next step, take a good photo and make mental notes of how the trigger spring and titanium trigger are arranged against the main spring of the mechanism before removing them.

Step 5: Remove pin that holds the trigger and it's spring to the case. These components will slide right out. Then remove the main spring from the case by sliding the last pin.

Step 6: Clean all of the components with a brush and the a grease solvent. I used Liftoff Adhesive/Grease/Oily Stains Remover bought from Home Depot.

Below is the photo of the components already cleaned and ready for re-greasing and reassembly:

Here is a closer look at the polished main component. One word to describe how it feels in my hand... solid.

hello i cant see the photos can you reload them