Can I lighten the trigger pull on my airgun?

[Dave R]

I just acquired a Beeman 650, with a trigger pull approximately 10lbs. Spec from their website is 3.5lbs, so not their best rifle, by any means.

Its a non-adjustable trigger.

I have done some light home repairs before (replaced extractor fixed a burr in the mag catch of my CETME, fixed trigger slap on a Century AK trigger group, etc.), and have not screwed anything up. Yet.

The trigger assembly is very simple. There's a catch on the mainspring, that hooks onto the sear, which is a piece of the trigger.

Am I likely to permanently ruin this gun if I attempt to lighten the pull, by smoothing, shortening, or reshaping the sear?

 

[Oldnamvet]

I'm not a gunsmith but have done trigger work. I have never tried reshaping the sear, etc. Most of the time I work with the trigger spring. At most, I will use a hard arkansas stone to smooth the mating surfaces on the sear, being careful to maintain the proper angles and not changing profiles. It takes me quite a while working slowly while I watch TV.

 

[Sunray]

I'd talk to Beeman. http://www.beeman.com/

 

[pedaldude]

it's possible the the sear is only case hardened, and not heat treated all the way through, that would mean that if you try to reshape the sear it won't hold that shape for long,

there is information all over about this kind of work as well as the checks to make sure that it is safe, and how to harden steel, but the trigger group might be pot metal, so maybe try just swapping springs to see if it can be lightened up a bit, cleaning and adding new lubricant can help in some instances as well.

keep researching and good luck,

 

[Dave R]

Have tried cleaning and lubing. Made a little difference, but not much.

The trigger is not pot metal.

Guess I'll try a call to Beeman.

 

[jaybar]

Adjust the sear engagement if possible.

I'm not familiar with the 650, but most airguns work the same way where the triger/sear movement releases something that smacks the valve open. Normally that something is not made of the same materials that sears and hammers are in cartridge shootin' firearms. Some light polishing to get rid of burrs is probably OK but likely won't help much. Some spring changing on the trigger return spring might help also. The more acceptable way to lighten the pull and give the crisper trigger that you need for precision air gun shooting is to minimize the sear engagement. Rather than changing the angles on the sear, minimize how much of the sear surface you have to disengage. Follow this link to an article that Don Nygord wrote on how to improve the triggers on the Daisy 717/747 models. You may be able to do something similar with your 650. Let us know.... http://www.novatech-group.com/bullseye/daisy717.pdf

 

[Dave R]

Great article!

My trigger is pretty different, though. There is a catch on the mainspring. And the sear, which is actually part of the trigger, catches that catch on the mainspring. So the full weight of the compressed mainspring bears on the sear.

The one principle in that article that makes sense for my primitive trigger is to reduce the surface area of the sear that the mainspring bears on.

That's a little intimidating.

 

[RecoilRob]

Before you start filing/grinding/sanding/stoning anything I would recommend checking the spring tensions....particularly the trigger return.

For some reason, the gun builders seem to love to put super strong return springs in guns. Some 'adjustable' triggers have screws to allow varying the preload on the springs. But, I have found many to have so strong a spring that they are WAY too heavy even with the 'tension' adjustment backed clear out.

Reduce the return spring until the trigger just barely resets. Shouldn't weigh more than a couple of oz. without the sear engaged.

If you need a light-weight spring for triggers, the springs under the keys on a derelict computer keyboard make good ones for target work. Ballpoint pen springs are another good source.

 

[Dave R]

I checked the return spring. Its not an issue. Very light. Just light enough to get the trigger/sear to catch that catch on the mainspring. That's where the 'torque" comes from. That honkin' heavy mainspring bearing on the generous sear that is part of the trigger.