Installing the Crosman 13xx/22xx Adjustable Trigger Sear

Monday, March 9, 2009

I cocked the unloaded, uncharged Crosman 2240 and handed it to my testing partner. “Give the trigger a squeeze and tell me what you think,” I said.

A few seconds later, the action clicked, and he said, “It’s kind of crummy.” I tried it and agreed. With a trigger gauge, we measured the weight of the trigger pull at four-and-one-quarter pounds.

To improve the trigger, we decided to install the Adjustable Trigger Sear for the Crosman 13xx and 22xx. Along the way, we learned a bunch of things that will help you install one on your own airgun. (Note that the Adjustable Trigger Sear [ATS] is not a factory authorized part.)

To get ready for installation, Make sure the gun is not cocked or loaded. Lay the 2240 on its left side with the pistol grip pointed toward you, and the muzzle pointed to the right. Next, remove the grip by removing the screw that holds it in place.

With the grip removed, you’ll see a view like the picture below.

With a pair of needle nose pliers or the blade of a screwdriver, slide the coiled spring off the post. When the spring is off the post, tug gently on the spring, and you will be able to remove it completely from the pistol. Additional note: you can defer removing the coiled spring until after you have removed the trigger side plate, but having the side plate still in place reduces the chances of parts being launched into the air (see note about cranky uncles below).

Before you do anything else, make sure the safety is in the FIRE position – protruding fully from the left side of the pistol with the red stripe show. Prop the pistol’s air tube up on a pad of paper or a paperback book – something that will elevate the air tube about one-half inch. This will prevent the safety from being pushed into the SAFE position. If the safety is pushed into the SAFE position when the side plate is off the trigger assembly, a tiny silver ball bearing and teensy spring will fall (or worse – FLY!) out, and YOU WILL HAVE THE DEVIL’S OWN TIME TRYING TO GET THEM BACK INTO POSITION! (Please believe Uncle Jock on this. It happened to me, and it made me very cranky).

Next, remove the two screws that hold the trigger side plate, and gently remove the side plate. In the picture below, you’ll see the original sear that sits on a pivot pin just to the rear of the trigger (in this picture, the original sear is overlaid on the ATS.) Remove the original sear but leave the pin in position. (Just to the right of the sear, you’ll see that teeny spring that I told you about.)

Put the ATS in position as shown below. Notice that it wraps below the pin that the original sear pivoted around, but unlike the original, the ATS doesn’t have a hole that the pin can be inserted into. This is true despite the fact that some ATSs have holes that might appear to fit over the pin. They don’t.

Put the trigger side plate back in position. Slide the end of the coiled spring over the end of the sear, and then slide the other end over the bottom post. You’re done, except for adjusting the trigger and replacing the grip. (Note: you can attach the coiled spring to the ATS and the post with the side plate removed, but I think it is easier with the side plate holding the sear and post in place.)

To adjust the trigger, follow the instructions that came with the sear.

In the end, the ATS tranformed the trigger in my 2240 from a creepy 4-1/4 lb affair into a very crisp trigger that sends the shot down range at just 1 lb 15 oz.

What to do if the little ball bearing and spring fall out. Make sure the safety and trigger are in proper position. Replace the trigger side plate. Remove the two screws that hold the trigger assembly to the air tube. As you look down on the trigger assembly from the top, you’ll see a small hole just above the safety. Drop the small ball bearing in the hole, then place the small spring on top of it. Now reattach the trigger assembly to the air tube. This will compress the small spring and hold it in place.

Note about Screw Starting Point Adjustments

The final, optimum adjustment of the 1st and 2nd stage screws will be determined by experimentation and a combination of the shooter’s personal taste with the particular manufacturing tolerances of the specific gun. Still it’s sometimes useful to have a starting point for the fine tuning process – kind of a home base – that represents average reasonable settings that the sear can be easily set to in order to begin the process in an orderly way, and reset to if the process goes awry.

Starting Point settings are defined so…

1. Turn the screw being set so that the tip is exactly flush with the surface of the sear.

2. Turn the screw clockwise by the number of turns (and fractions of a turn) indicated in the figure.

Here are Starting Point settings for the three styles of Crosman sears. To identify which style you have, check for:

1. Presence of the two fabrication alignment holes present in styles A and C but not B.

2. The square “heel” of style A that B and C lack.

Til next time, aim true and shoot straight.

– Jock Elliott


  1. Pete White says:

    I have spent hours reading about 2240s. You are the first to write about the safety position when disassembling and how to reinstall the spring and ball. Good job. Thank you for saving me lots of grief. I don’t like to get cranky either.

    GMax just takes it out and does not even bother to put it back in in their youtube instructions.

    i don’t see the safety need for a single shot bolt action pistol. Best safety is don’t load it unless you mean to shoot it.

    1. Jock Elliott says:


      Thanks for the kind words and good luck with your 2240 projects.

  2. Raoul says:

    I own a Crosman 2300KT which has a creapy trigger. I read your write up on the 2 stage sears and notice that you mentioned 3 types of sears and the adjustments. Which one would I need and where would I obtain one. Any sugestions on taking out the side wobble/slop on the trigger plate.


    1. Jock Elliott says:


      Contact the good folks at and they can advise you on those excellent aftermarket trigger sears.

  3. Slinging Lead says:


    You can use appropriate sized (small) washers placed on the trigger pivot pin to take out the slop on the trigger. My 1377c came with a thin washer I bent across the middle. The resulting arc shape bore against the trigger when the sideplate was closed up, and took out the slop.

  4. Alex says:

    Thanks for the info on the spring and ball. But what is the position of the safety? There is a slot, should it be up or down? My model is the 2300S.

    1. Jock Elliott says:


      Make sure the safety is in the FIRE position – protruding fully from the left side of the pistol with the red stripe showing.

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