Need some quick advice on increasing trigger pull weight
:hoot:
My eyes are failing, so I’m just going to ask…how do I increase the trigger pull on my .25 Vulcan? Right now, it measured in an ounce or two, no accidental discharge, but needs to have the sear release pressure increased. Is there a simple way to do that?
I had the linkage apart last night, adjusting the safety friction fit to the trigger to avoid the safety slipping off when the gun is cocked. But damned if I can figure out how to increase that trigger/sear release pressure.
Hoot:
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Viewing 9 replies - 1 through 9 (of 9 total)
To give an idea of pull weight…..
My 1st stage is adjusted (ball point pen spring on trigger rod) to 150 gm (5.3 oz)
2nd stage (with sear spring hooked on screw in middle hole) fires at 480 gm (17 oz)
That makes for a light 1st stage, but easily felt increase in pressure to move through 2nd stage. I definitely want an easy to feel start of 2nd stage and the loosest (top hole) position was too little resistance. In the loosest position, just lights tapping 2nd stage with the trigger caused visible sear motion. I didn’t want any sear motion with just a tap. Otherwise, a balk fire (touchling 2nd stage, but abandoning the shot) would leave the sear in unpredictable, unsafe engagement.
Don’t think I would want it any lighter. If anything, a tiny bit more on either the 1st or 2nd stage to total 500 gm would be needed to get to 10 meter gun spec.
My 2nd stage travel is very short. I adjusted the sear overlap to about 1.2 with the bottom trigger screw. Any less overlap and I would fear accidental firing. Even with 1.2 mm of sear travel, the trigger blade moves very little from beginning of 2nd stage engagement to firing.
Over travel was adjusted to be practically nil via the top trigger adjust screw. (basically turn it in until it stops against FIRED sear, then back off just enough to let sear fire freely)
TIP, you can test fire just the trigger mechanism without opening the poppet valve by undoing your hammer spring completely. You’ll need to open the right side inspection panel. Notice the long pin the the cocking level pulls against to set the sear? Leave the cocking knob pulled back halfway. To cock the trigger pull back on that right side pin. This cocks just the trigger mechanism and lets you play with the trigger repeatedly without the pop of air discharge.
AND make sure the spring extension is resting against it ❓
OR, maybe you inadvertently turned the trigger frame the wrong way and shortened the trigger link too much ❓
:hoot:
Yep! You hit the nail on the head Lurker. I over-corrected to solve a problem of too loose of a safety caused by the missing spring/ball detent meant to hold it in place!
Hoot:
:hoot:
PROBLEM SOLVED: Here’s what I found….
1) the safety spring/detent ball are both missing. This caused the safety bar to slide back/forth too easily to be reliable when the gun was cocked.
2) to correct this, I rotated the trigger assembly linkage rod to move the trigger’s safety catch “down” further to hold the sliding safety bar in place when the gun is cocked.
3) result…too short of a release on the sear. It wasn’t too light of a pull on the sear, it was too short of a pull to release the sear.
Corrective action…find a spring and ball detent to put under the safety slide bar so I can rotate the trigger assembly back to where more length is added to the sear pull, prior to it releasing. That will correct my dangerously light trigger release!
Thank you gentlemen. I never knew there was a spring/ball detent under that safety slide, because I never had it off before. I don’t believe it was ever installed…perhaps I’m wrong, I’ve been wrong before, but at least now I know how to get that safety slide to stay in place when the gun is cocked. Now…to find a hardware store that sells individual ball bearings. Any idea of the size of the spring and ball bearing? I’m going to either have to write Eugeny and buy replacement parts, or just get “close enough” with non=metric spring/ball to add to the safety.
Problem figured out…now I can get parts and resolve it!
Hoot:
Sooo…….did you move the silver screw yet ❓
AND make sure the spring extension is resting against it ❓
Or could the sear be set on the hairy edge ❓
You might try giving the seer a bigger bite.
OR, maybe you inadvertently turned the trigger frame the wrong way and shortened the trigger link too much ❓
:hoot:
It’s the second stage “let off/sear release” I’m concerned about.
The first stage is fine. The 1st stage spring is right where it needs to be as far as “pull”, and the safety is snug.
It’s the near immediate and light release of the second stage that I want to add a few ounces to, so the gun won’t have such a “hair trigger”
Hoot:
the spring on the link is the first stage only, if we talk about the first stage, yes replacing the original spring with a ball pen spring and setting high precompression on it is the way to go.
H00T,
Did you release the trigger link spring tension by moving that little collar on the trigger link ❓ And that spring has to butt up against the rear of the trigger mounting frame. Moving that spring collar makes a difference.
Then there is the trigger weight spring that I unlatched on my .22 to lighten my trigger pull. It has a silver screw in the left side of the Frame that the spring normally rests against. The screw can be moved forward into another hole
to increase pull. Mine was in the rear of 3 screw holes. Move the screw forward to another hole and latch the extension of the apring on it. That should help.
Did you get the tiny safety detent ball and its tiny spring back under the safety slide ❓
I had to use a magnet pick up tool to find mine under the frig :butkick:
can you see the silver flathead slotted silver screw
at 4:34 min
I think it needs to go to another slot.
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Good info again guykuo :thumb:
H00T,
Someone else has had to install a missing safety detent and spring. Its in the Vulcan forum somewhere ❓
You must have missed my post about the manual lacking both description and diagram of the safety detent setup.
My safety slide had very slightly burred edges that made it feel a little gritty. I must have had my hearing aids turned up and luckily heard the detent ball hit my kitchen linoleum floor. While looking for it I found the tiny spring also. Once the slide was honed, lightly lubed, and all back together it is smooth and has a positive but easy moved detent action. I still had to make a slight adjustment to the trigger link and found a ballpoint pin spring to lighten trigger pull slightly. Also I switched the two trigger LOP screws so I have a more central adjustment on both.
I really like the manual diagrams and parts listing. Its very well done ❗
With a few exceptions mostly due to improved parts. The quantity of a couple O-Rings is short as well as a couple screws in mine are shorter than specified.
I love the safety when smoothed and properly adjusted.
I set it before cocking while manually loading single shots and before inserting a magazine or before inserting an indidual pellet. I still need to carve a pellet tray. Or if someone has a broken magazine it could be glued in last shot position and part of the top cut off 💡
Once on target and ready for action just a little pressure of the nail side of the trigger finger moves it forward. I only reset it when changing magazines.