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rsterne · Moderator

For many of you this is nothing new.... but I found it on the Internet and decided to try it out.... It works GREAT!.... I added three 4-40 SHCSs to adjust the length of the first stage, the overtravel, and the sear engagement.... For these mods to be effective, you will have had to already replaced the trigger (coil) spring with a lighter one to reduce the initial trigger pull and introduce what is effectively a first stage.... I use a 3/16" OD spring, 5/8" long, made of 0.020" wire to replace the stock spring which is 0.028" wire.... Other mods are polishing all the metal to metal contact points on the hammer, sear, and intermediate lever to at least 600 grit or finer.... If you want to reduce the 2nd stage pull weight, you can bend the sear (hairpin) spring to have a tighter angle but GO EASY.... Just 5 degrees makes a BIG difference.... 10 degrees and it will fire when you breath on it.... Shocked

The upper screw on the back of the housing adjusts the trigger position.... Screwing it in moves the resting position of the trigger aft and hence shortens the first stage.... If you screw it in too far, the gun will not cock or may fire when bumped, so BE CAREFUL....

The lower screw on the back of the housing adjusts how far the trigger can move backwards.... Screwing it in reduces how far the trigger can move back after it is pulled and hence reduces the overtravel.... If you screw it in too far, the gun will not fire....

The screw on the bottom just in front of the trigger guard adjusts the sear engagement.... Screwing it in reduces the sear engagement, reducing or eliminating any creep.... If you screw it in too far, the gun will not cock or may fire when bumped, so BE CAREFUL....

Now the "how to" part.... Get three 4-40 socket head cap screws, two that are 1/2" long, and one that is 3/8" long.... There are already two holes in the back of the trigger housing and all you have to do is screw the two long (1/2") screws in there.... no tapping required because the housing is plastic and grips the screws nicely, preventing them from losing their adjustment.... Drill a 3/32" hole (or a #38-#39 if you have one) vertically just in front of the trigger guard.... Line it up carefully on the centerline of the trigger housing and make sure to drill straight up and not on an angle.... Then insert the shorter (3/8") screw into the hole and screw it in, stopping when it JUST contacts the intermediate lever....

To adjust, first make sure that all three screws are not interferring with the action of the trigger.... Reassemble the trigger group, and install it on the action. You have to install the safety, as it tensions the sear (hairpin) spring and the gun is unsafe (it may not even cock) without it. Make SURE the gun is unloaded (no pellet) and pointed in a safe direction and then cock it.... I made my adjustments in this order:

1. Sear engagement: From the point where the front screw just contacts the intermediate lever, screw it in slowly, counting flats on the allen key, until the gun fires. Mine took only one turn (6 flats). Then turn the screw out a flat at a time until the gun cocks safely and will not fire with any amount of banging around. That is the MINIMUM safe sear engagement. My gun would not cock reliably with the screw out 1 flat from where it fired, and at 2 flats out it would fire when bumped hard. At 3 flats out, I could not make it fire no matter how hard I bumped it. Note that is only ONE-HALF TURN from where the screw first contacted the intermediate lever - so this adjustment is CRITICAL.

2. Trigger overtravel: This one I found pretty easy. I screwed the screw in until when I pulled the trigger the gun would not fire and then backed it out while holding pressure on the trigger until the gun fired. I then backed it out two more turns. Four turns out allowed the original travel, so I had reduced the overtravel by 50%. Set this however you like it. Note, however, that if you reduce the travel too far, the sear will drag on the hammer and produce inconsistent velocities.

3. First stage length: As you screw this screw in, it moves the resting position of the trigger back, shortening the first stage. I found that I liked it with about 1/8" of travel in the first stage, measured at the tip of the trigger blade. You may like more, or less, it's a very personal thing. Remember, however, if you eliminate the first stage completely the gun may be unsafe as you may actually be removing sear engagement.

Pop the safety out, reinstall the action in the stock, and re-install the safety and try her out!.... I can't believe the improvement.... Mr. Green

Bob

AirGunEric · Site Admin

I have seen that screw setup somewhere before (CrookedBarn I believe)- and it does work well?

rsterne · Moderator

I got it from a Internet video.... it's not new, just new to me!....

Yes, it works EXTREMELY well when combined with a lighter trigger spring.... Mr. Green

Bob

Mark5043 · Silver Status Member

http://www.youtube.com/watch?v=bWWH8_SRCvg

Mark5043 · Silver Status Member

I'm playing with the idea of doing this mod..."Just took a trip to the hardware store for other supplies for another project"I will say though that I'm pretty happy with my stock trigger.While obviously not a match grade set up...it breaks clean,and crisp out of the box imo....

packrat · Senior Member

Mark---if you think the trigger's good now...do those mods and you'll think it's outstandingly stupendously amazing !! I di it to mine when Bob first posted that and I was totally in awe of what a difference it made..What's really cool is how much more accurately you can shoot with a really fine trigger, compared to just a good one Mr. Green

Mark5043 · Silver Status Member

Okay guys I give!..... Laughing

I've heard nothing but good things about this mod, so now I have to see for myself...... Cool

broommaster2000 · Moderator

I'm gonna get a used one next week. Embarassed

Mark5043 · Silver Status Member

rsterne · Moderator

I have run into one problem using these mods.... If you remove too much of the overtravel on the trigger, the sear cannot move completely out of the way, and will drag on the hammer.... This causes low velocity and can cause terrible inconsistency and accuracy problems.... Shocked

If you are experiencing this after modding the trigger.... try increasing the overtravel.... I'm betting the gun will go back to behaving normally.... Wink

Bob