Daisy 880/901 trigger mods

[T.J.]

NOTE: I updated this post to change the term "sear" to "flat spring" for consistency, since that seems to be the preferred term by those who have contributed to this post. - T.J.


I have been working on the Daisy 880 trigger for a while, and have come up with some mods that lighten the trigger pull. I have been preparing an 880 for a local air gun silhouette shooting event. The Daisy has the power and the accuracy for the event, I but needed to do something about the trigger.

In order to explain the mods, I think it would be useful to discuss how the 880 trigger works:

* When the bolt is pulled back it pushes down on a lever at the back of the hammer, rolling the hammer back and closing the valve.

* As the hammer rotates back, the hammer spring pushes on the trigger, which repositions the trigger into the firing position. The trigger also has a stop that locks the forward movement of the hammer, so the hammer cannot rotate to the valve open position unless the trigger is pulled.

* The trigger is pegged to a bent steel plate that slides above the hammer pivot. This plate also moves back as the trigger repositions to the cocked position, and it locks the trigger in place. I am going to call this bent metal plate the flat spring (see unmodified flat spring jpeg). You can see part of the flat spring angling up out of the “valve body” (#8 on the 880 parts diagram) if you pull the bolt back and look in the slot where the bolt lever moves (see flat spring in valve body jpeg).

* As the bolt is pushed forward, the bolt block depresses the flat spring, and the front edge of the flat spring engages a step in the aluminum valve body (see flat spring on the step jpeg). This unlocks the trigger.

* When the trigger is pulled, the trigger pushes the flat spring forward and the front edge jumps off the step. As the trigger rotates forward, it compresses the hammer spring and unlocks the hammer, driving open the valve.

In looking at the step where the flat spring engages on the valve body, I could see that the front edge of the steel flat spring was digging into and hanging up on the aluminum step. The front edge of the flat spring had sharp corners from being stamped and formed.

I think the flat spring sticking on the aluminum step is what caused the heavy but crisp trigger pull. After a bit of trial and error, I found I could lighten the trigger pull by bending the front of the flat spring downwards and polishing off the sharp corners. This allows the flat spring to still engage on the step, but it now it slides past the step when the trigger is pulled rather than sticking and jumping off.

The front surface of the flat spring that engages the step is very short. To modify it, I clamped the short front surface of the flat spring in a smooth-jaw vice up to the first bend and then just pushed it a bit with my finger. It took a few tries to move it to where the front surface would slide past the step rather than stick to the step (See modified flat spring jpeg, left side in the image). As you can see on the modified flat spring, the front surface is no longer parallel with the back surface; it is bent down a few degrees. The flat spring was lubricated with a Teflon based bicycle chain lube during reassembly.

Another mod I did was to replace the hammer spring with a shorter, stiffer one (1 3/16 X 3/8 X .054 Ace #136). I cut the spring to be ½ inch long. This was done mostly to make it a lot easier to reassemble the trigger, because there is no preload on the spring. I think the stiffer spring also takes some of the squish out of the trigger (see hammer spring jpeg).

The third mod was to make a trigger shoe out of a piece of wood and glue it to the trigger. The shoe widens the contact surface from ¼” to ½”. It also reduces the curvature of the trigger (see trigger shoe jpeg).

I have been testing the trigger for a few weeks and have not seen any indication that it will accidentally discharge from a bump. Cocking the 880 does not put pressure on the flat spring to release, because you have to pull on the trigger to supply the pressure. However, please proceed carefully with any trigger mod, and test it to make sure it still works safely. These mods are reversible if you decide you don’t like what they do.

YMMV

Tradeoffs
* Slightly less crisp release but I think more predictable

[DavidS]

Nice trigger mods.   Though I would highly recommend putting stiffer Trigger/Hammer spring back in that is at least as long as the original, this is because you are slowing the opening of the valve causing it to waste more air by expelling more into the barrel after the pellet has left the barrel, and you are also reducing the power as a result.

You can make a trigger stop to shorten the pull by quite a bit while still maintaining the stronger longer spring.

Just my two cents.

[T.J.]

I was concerned about that, but I do not have a chrony or some other means to measure before and after effects of the mods. I would be very interested if someone who can measure trigger pull and FPS would try the mods and see if there is an impact on performance.

T.J.

[DavidS]

I was concerned about that, but I do not have a chrony or some other means to measure before and after effects of the mods. I would be very interested if someone who can measure trigger pull and FPS would try the mods and see if there is an impact on performance.

T.J.

I stopped calculating FPS do to not rely being needed.   Now I use penetration in a dry phone book and consistant pellets as well as how many times a known spinner rotates to compare power when power modding.

As to trigger pull you can use an analog fish scale (like the ones with the slide scale for indication).

[T.J.]

Hi David,

I could probably do the phone book test and report results. Do you have standard setup -  pellet types, distance, number of pumps? I would need a baseline to make a comparison. I have 7.7 grain wadcutters, and there should be an order arriving this week with some Beeman 8.3 grain pointeds and some Winchester 9.8 grain domes. I will need to check at WW for a fishing scale. I have a spring loaded one, but I don't think it is very accurate.

T.J.

[DavidS]

Hi David,

I could probably do the phone book test and report results. Do you have standard setup -  pellet types, distance, number of pumps? I would need a baseline to make a comparison. I have 7.7 grain wadcutters, and there should be an order arriving this week with some Beeman 8.3 grain pointeds and some Winchester 9.8 grain domes. I will need to check at WW for a fishing scale. I have a spring loaded one, but I don't think it is very accurate.

T.J.

As far as a standard setup it has been a while.   All of my Daisy 880's/901's are modified for additional power.   Though if I remember correctly the 880's did about 300 pages plus the cover on 10 pumps stock.

Unfortunately I moved half way across the country about 4 months ago and still have not yet located all of my notes.

[T.J.]

Dug  out the fishing scale last night. It shows the trigger breaking at about 4 1/2 pounds. I saw in another forum where someone measured the stock trigger at 8 pounds.

T.J.

[saxpride]

Thanks TJ for your post,

I've been wanting to lower the trigger pull on my 901, and after much reading and browsing on these forums, finally some pictures!!!!

I'll get to it when I have time, but just wanted to give a big thanks for taking the time to get some pics up on how you modded your trigger. I'll post my results when I have time too. thanks!

SS

[saxpride]

So I cracked into the 901 tonight, and I got to admit I'm a bit timid to really getting into the trigger assembly. Is there a write up as to getting into the trigger assembly?

As a matter of fact, is there a write-up on how to get into the receiver? One that includes pictures. I love the information this board has to offer, but I feel like there is a lack of pictures / videos. That would really make the difference, and would help newbies get into the rifle too.

[dmoneytt]

Don't bother pulling the gun apart for polishing and spring changes and stuff.  You can easily get a Daisy 880, 901, or 35 to have a beautifully crisp and light trigger with one super-simple mod.  Just remove the buttstock and take a look at the back of the trigger blade.  See how it has a tab on the back of the trigger that sticks down below the metal tabs inside the receiver when the gun is cocked?  Cut a shim from a soup can that will fit tightly behind the trigger when the trigger is pulled and the stock is reinserted into the receiver.  The shim will sit inside the two metal tabs on the internal receiver.  What this does is keep the trigger from returning far enough to let the rifle cock until you have carefully pulled forward on the trigger blade hard enough and far enough to let the rifle cock.  This lets you pull the trigger forward just enough to bend the shim so that the trigger will reset and you have almost zero pre-travel prior to the hammer's release. Once you have the shim bent just the right amount, it will stay in that sweet spot of minimal pre-travel for every future shot. It also provides some spring tension to assist in the trigger pull.  My Daisy MSP's all have this 1 minute free mod done to them and they all have triggers that are under 3 lbs, and are, more importantly, ridiculously short and crisp.  This simple trick makes any other trigger work unnecessary.  Try it and you will be a believer.  Also, don't ever use a shorter or weaker hammer/trigger spring if you care about consistency and power.  If anything, a similar length but heavier spring would be better.

[ToRmEnToR]

That's Money! lol.. That's one I'm going to have to try! I was concerned about hammer spring/valve pressure, but that way seems to circumvent that .. Thanks Money..

[saxpride]

I did dmoneytt's trigger fix. Early testing shows that, it works! Took me a looooong time to find out what is going on, but now that I've gone through all of the brain damage, I have to say so far it's working very well.
The trigger pull...I would guess is around 4 lbs. Very crisp. Strong improvement over a stock trigger. No other modifications.

I used a slightly thick piece of metal, similar to a tin can. Basically it's similar in thickness of a penny. I trimmed it to be slightly narrower than the width of the trigger itself. Length wise, something under an inch.

Anyway, I took some photos. I hope this helps people who are visual learners.

Tips for those who are wanting to try it out.
It is a pain in the butt assembling everything together and keeping the shim in place. Design your shim so that it stays in place better. My shim had a natural curve to it from cutting it with metal sheers, probably made it easier. Follow the next tip to help it stay in place.
Store the rifle in the cocked position, or when mobile. My shim almost fell out of place a few times. When the rifle is cocked, the shim stays in place. When it's uncocked, the shim is loose.

[DanD]

I did the trigger shim mod last night, and it works magnificently so far. I cut a rectangle from a soup can lid and folded it in half so it sandwiched the rear of the metal receiver tabs with the fold sticking out rearward enough so the butt stock holds the shim firmly in place against the back of the trigger blade. The shim cannot be seen when the gun is assembled. Just like dmoneytt explained, once the shim is in place, you cock the gun and push forward on the trigger to bend the malleable shim enough for the gun to cock. The shim holds this shape and limits forward travel of the trigger blade so you are left with a crisp and light single stage sporter trigger. It took me about an hour to figure it out, but the results are excellent. dmoneytt, or whoever thought up this mod, should get a Nobel Peace Prize for Kitchen Table AirGun Modding. I'm sorry I was so wrapped up in the work I didn't think to take pics.
Make sure your safety is off before removing the plastic receiver covers, otherwise the safety will come apart and the detent ball will go a-flying. Luckily, I found mine.
I was impressed to discover that the gun was very clean inside with little dabs of grease already applied on the trigger contact surfaces from the factory. This $45 dollar Walmart special is one neat little rifle. It was already shooting decent groups. Can't wait to see what it can do with a good trigger.
Have fun,
-
Dan

[Missed-Em]

Anybody else try dmoneytt's fix for the trigger?  I think I'll try it, but last time I tore my 880 down mystery parts appeared.  Any more hints, tips, suggestions for the 880 trigger?

[saxpride]

Just go for it!

The mod is still working very well for me, it's totally reversible, an you don't have to get deep into the workings of the gun to get to what you need.

To set off the trigger, you need to hold down the metal blade, on the top of the receiver, THEN pull the trigger.

To cock the hammer, just mush it down.

If you have questions let us know!   Good luck1!!!

[BigTinBoat]

Anybody else try dmoneytt's fix for the trigger?  I think I'll try it, but last time I tore my 880 down mystery parts appeared.  Any more hints, tips, suggestions for the 880 trigger?

I just got time to do mine. It definitely makes it lighter. I think mine is under 2lbs.

Like SS said - it takes some thinking to see what it does, but I did it. I think it basically works like the travel screw to take up the first stage ion a 2 stage trigger. On my older 880 the trigger guard and safety comes off of the receiver. All I did was crazy glue 2 thin brass washers to the back of it. Works like a charm. Trigger was so easy I thought it might fire with a bump, but I knocked all over the receiver and could not get it to go off without pulling the trigger.

[DanD]

Picture of the can lid shim. Another detail is the safety engagement block  will not clear the safety tang on the trigger blade now that the forward travel of the blade is limited. The safety engagement tab needs to be shaved down if you still wish to use the safety.  Don't ask how I know this, but be careful not to go too far or the safety will push right out of the housing. I attached a pic of the safety to show what area needs to be cut away.

[DavidS]

Well for me the safety is meaningless.   I was taught never to rely on a mechanical safety, only the shooter can provide safety by there habits (in other words use the safety between your ears).

As for the shim trigger mod I am interested, and will be trying it as soon as I find a thin peice of metal to do the job.   Thank you for the suggestion, it seems obvious in retrospect, though I did NOT think of it.   Thank you.

[stonykill]

 OK, going to have to try Moneys mod. Thanks!!!

[dmoneytt]

Oh yeah, good point about the safety being negated guys.  I probably should have mentioned that when I made my original post.  I came up with the idea when I first disassembled the gun and looked at putting in a pre-travel screw.  I just saw that a soup can shim would be easier than drilling and threading in a screw, so laziness won out on that.  I did end up installing an over-travel screw through the trigger guard.  These triggers can be made really nice with very little effort.  My 901 doesn't group as nicely as my old 880 though.  The 901 will do about 3/8" at 10 meters, while the 880 was closer to 1/4".  Glad this little mod has helped some folks tame that awful factory pull.