Hi Folks, I have a 34 in .177. It is already tuned with a JM kit, but I am interested to know how to work the T05. Is there a documentation available somewhere? Or is it just simple as working the single screw clockwise and counter-clockwise?

depending on what results you want to get.

here are the basics. the single screw for the most part adjusts the length of the first stage. it is not designed to adjust the second stage pull weight nor is it designed to adjust sear engagement depth. those things are fixed by design. having said that, the trigger works by having that single screw trip a rocker which is a lever arm. this sets some things in motion that ultimately results in the release of the sear. when you adjust the position of the single screw to change length of first state you also re-position its point of engagement along the lever arm. subtle but there none the less. that repositioning changes the effective lever length and at least gives the impression of a slightly lighter trigger or harder trigger. the difference is subtle and limited in its range.

if you want to impact the weight of the trigger pull and the depth of the sear engagement in a meaningful way there are a number of opeations to be performed.
you can start by polishing the surface of the rocker where the screw makes contact. be careful not to alter the contour. you can do this by using an arkansa stone or a piece of 400 wet or dry on a flat surface and running the
rocker over it front to back. i then polish on a wheel with metal polishing rouge. next you can polish the sear slot but i don't mess with that. lubing the rocker surface with molly has some effect as well. this will lighten the pull a little since you have eliminated a small amount of friction.

next step you can cut the sear spring and trigger return spring 1.5 coils. that will lighten the trigger pull some. a better alternative is the
replace the sear spring with a lighter spring of the same length. somewhere on this site is a link to a company that sells such a spring. i went through my office and canabalized a bunch of ballpoint pens till i foud the spring i thought i wanted to use and then cut it to length making it slightly longer that standard but it is still softer. works well for me on my 52.

if you want to carry it further (depending on your abilty) you can install a second screw that will adjust the depth of sear engagement. that will also lighten the trigger pull. i would let that go until i had done everything else because you may find that a few simple operations get you where you want to go. installing and adjusting that second screw carries some risks of creating a dangerous trigger which i think is why diana eliminated the T01 trigger.

it is alos a good idea to take the latch plates out and remove burs and molly there surfaces that slide against each other. be sure and note the direction they face because the two surfaces have different topographical features. bevels to the rear. this won't make trigger pull lighter but make things work mfore smoothly while cocking the gun since the piston rod slides into the hole in these plates and is gripped by them before trigger release.

Hey Larry, very nice explanation of the TO5. Wish we could get together for a beer!! I'm sure we could talk one another's ear off, but what fun!!! Where do you live?? I live in Springfield, Massachusetts. Just finished jeweling a compression tube for a 48. My friends are dying to see it. I think it came out great. Some little changes for the next one, but not much. Really does look nice. Just a little bling my friends are asking for. Got to keep them happy you know. Have a great evening - Lee

Larry:

very well explained and the ball point spring example is down to the ground explanation

could not have typed any better

warren

and remember "it's 30% the gun and 70% the shooter"

Thanks Larry, indeed quite a detailed explanation. For now, I think I will just play with the screw to see how the trigger changes behavior.

Go to MSC Industrial Supply Company and order this pack of springs...

http://www1.mscdirect.com/CGI/NNSRIT?PMPXNO=3348059&PMT4NO=0

...Simply remove the factory seer spring and install this one.
I have $75 in research finding this spring. So, it's like shareware. If you try it and like it, send me something.
I don't know what the pull is but it's much better.
Make sure the gun is unloaded and uncocked. Remove the action from the stock. Remove the cover at the rear of the action tube. Pull back on the safety until it comes off. Don't move the flat bar that goes down the center of the trigger assembly. Pry out the factory spring with a small screwdriver by picking it out of the small pocket at the bottom of the housing. Use a small pair of needle nose pliers or tweezers to put the MSC spring on the tab that sticks down from the seer and drop the other end into the pocket at the bottom. Push the safety back in. Put the cover back on. Put the action back on the stock. Test the gun. Send me a tin of Beeman FTS pellets.
Easy.
Rob

of removing and reinstalling the spring. that was missing from my post.

i live in southern califoria. year round everything. on the same day i could surf fish in the morning and winter mountaineer with ice axe and crampons in the afternoon. this saturday i will compete in field target in the morning and on sunday i will do a 40 mile bike ride to huntington beach and have breakfast with my cycling buddies.

Separating the two requires the addition of a second screw.

your post is confusing. clarify. thanks

The screw does both--lengthen first stage while simultaneously decreasing the 2nd stage let-off weight. Take out the blade and look at the fulcrum arrangement of which the screw is an integral part--or just adjust the screw to various settings and measure the let-off weight with a trigger scale as you do so.

You're welcome.

but the range of adjustment is limited. with the second screw you can have a short first stage AND a light pull. my experience is that you have to make the first stage rather long in order to lighten the pull of the second stage. i really don't like the first stage to be too long. others may like that and if so may not need to mess with a second screw. simple is good.

hw rekord triggers have a clunky first stage adjustment. a metal tab that you have to bend. at lease we can adjust with a screw. they do include a sear depth screw (that is hard to get to) and a trigger pull weight screw. i think though that the T05 can be made just as nice if not nicer than a rekord.