Stock 2 / Stock 3 : One piece sear installation guide

[MemphisMechanic]

First, thanks a ton to Johnbu for the help (via phone calls and texts at 11pm!) in getting my gun up and running with the Titian/Bolo/Extreme sear combination.

These guns are rather easy to work on, although that won't be apparent until you're done. I promise you can do all of it yourself if you own a hammer, roll-pin punches, pliers, and a dremel with polishing accessories.

The hard part for most is installing and fitting the 1-piece Xtreme sear. Probably because it's the part with the least documentation online.

Let's change that.

 

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

All you're going to disassemble on the gun are very easy things:

1. Drive the small roll-pin out of the right side safety and remove it from the shaft. (If your gun has an ambidextrous safety.)

2. Lift the leg of the sear spring up off of the safety and onto the housing.

3. Pull / tap the left side safety out.

4. Push in and forward on the sear cage and it pops right out. That's it!

For more info: refer to these videos for step by step assembly & disassembly. If all you're doing is installing a 1-piece sear then you can skip directly to the steps on removing the safeties. (the sear housing pops out with a tap once the safety is removed) 

 

How to take your Stock II or III apart:

https://youtu.be/oxA-rCdgXxU

 

How to put it back together:

https://youtu.be/dUcFuy1B65Q

 

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

You'll be faced with this now.

On the left side of the photo is the thin second piece of the sear. It's the part with the round hole facing upward that has a spring's pigtail sticking up into it. This leg is lowered as the trigger is pulled to disengage the firing-pin block. (It works the opposite of a firearm like the Glock or M&P, which are raised when the trigger is pulled.)

This second piece of the sear has an extra spring, and is therefore responsible for a slightly higher trigger-pull weight.

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

When I was about to fit my Xtreme sear, I took a bunch of pictures detailing how the factory 2-pc sear and cage assembly went together.

Don't bother.

Note exactly how the wider coiled spring in the center of the sear is installed (in the above photo) because that's the only thing you need to replicate with the new parts... then take a punch and push the pin out, allowing everything to fall apart. 

I barely needed a tap from a hammer. It's not a press fit.

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

Next I took Johnbu's advice and made a slave pin out of a Q-tip cut down to the same width as the Xtreme sear.

Assemble the sear and spring as shown.

(Note: Per Johnbu's advice, I polished the sides of the sear and inside walls of the cage, the pin,  and the pin holes in both parts. Per his conversation with Eric Gruaffel the new one is still only surface hard, so I didn't polish engagement surfaces.)

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

Photo 1: Ease the sear into the cage from below, making sure the long leg of the spring ends up on top of the cage as shown.

The short leg of the spring should also face up, pinned against the center part of the sear.

Photo 2: Move the long spring leg into this notch to take the stress off of it, and push the sear up and forward into place. Everything should now be arranged for you to slide the sear pin in from the side... push it in or gently tap it into place. Not much force will be required.

As you push the Q-tip out of the far side, things may bind up when the steel pin runs into the side of the sear spring. A small pick or punch can be used to push the coils into line so that you can press the pin all the way home.

The sear cage is ready to go back into the gun, except that the long spring leg is going to be in the way of the safety's pin.

Photo 3: Take the tip of a pick and push the spring leg up like this, and it'll stand up in exactly the position shown. Every single time. 

Grab the tip of the spring leg with needle nose pliers, and move it over to the small notch in the center of the sear housing where it began when you disassembled the gun. That's where you'll see it for the remainder of the photos.

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

Next, reinstall the cage into the gun's frame.

Simply press it down and back into place, then reinsert the safety through it to retain it. That's it.

Oh, you'll be fighting the hammer and mainspring the whole time. See the reassembly video linked above to see what you're supposed to do.

Now, on to fitting.

This is where text gets confusing. So let's begin with pictures and video instead.

The image below shows what your problem is going to be. There is a bump on the safety's pin that needs to be able to rotate UNDER the sear's short leg when you flick the safety into the upward position. The safety locks under the sear, and prevents the trigger from being able to rotate it downward.

IMPORTANT: This means you're grinding on the underside of that sear leg. You aren't making the tip of it shorter. That's how people have ruined sears.

[MemphisMechanic]

That photo doesn't show it all that clearly. So here's a video of my gun with the sear fitted and able to be engaged/disengaged. This should make things clear to you:

When you first put the sear cage in, you probably won't be able to do that. 

But you'll be able to see where your parts are colliding.

Right...

Edited November 17, 2016 by MemphisMechanic

[MemphisMechanic]

...here...

Trim that spot until your safety can slide underneath it and will engage with the hammer forward, half cocked, and fully cocked.

(You can also grind down the bump on the safety's built in pin. The safety is more expensive if you mess up... but it's easier to test fit it.)

That's all there is to it.

FINAL NOTE: Make sure to place the long leg of the sear spring back into groove in the safety's shaft before installing your slide, or you'll bend (ruin) the spring and gouge the bottom of your slide.

If you're installing a Titan/Bolo combination or other combination of trigger parts, you can focus on fitting them now. I got lucky and didn't need do any fitting at all.

Edited November 17, 2016 by MemphisMechanic

[bigbob21]

Thanks for posting this... I went through this a couple months ago and this is a very good guide.

One tip that I read was: if your afraid of grinding too much off of the sear, just go until your safety engages/disengages with your thumb.

I got mine to work with a slightly heavier engagement than how it came stock and stopped there. Over the past month or two, with all the dry fire I do, it eventually broke in nicely and is a lot easier/smoother.


Sent from my iPhone using Tapatalk

[MemphisMechanic]

Johnbu said the same thing. If you can engage the safety in all three positions (hammer down, half cock, and hammer back) stop there.

I removed a fingernail's width worth of material I would guess. It fit perfectly on the second try, and was initially hard to activate.

Flicking it on and off a couple of dozen times, it's already just as easy as the unmodified gun was.

[ryridesmotox]

Good writeup

One note on the disassembly instructions in post 2. After you remove the roll pin holding the right side ambi safety lever... The sear spring leg pointing forward needs to go in the little notch toward the center of the gun. That disengaged the sear spring from the safety lever bar so you can remove it. 

When I did my fitting, I fit the safety bar to the sear. The sear is cheaper to replace, but you also have to remove it from the cage several times, each time more annoying than the last. 

Edited November 17, 2016 by ryridesmotox

[Bapple]

My first post here on these forums.  I am a brand new production shooter (still have not shot my first match yet, but soon I hope) and I have been shooting a Stock 2 recreationally for a while.  Maybe have 1500 rounds through the gun now.  Been hesitant to try anything like this although I have wanted to smooth out the trigger somewhat.  Think I am gonna give it a try and do this myself after seeing your thread.  Thanks for the tutorial and info, much appreciated.  

Hope to get this done myself soon, as there is a club USPSA match nearby in 2 weeks and I hope to make it my first match.  Let me know also if you have any tips for a new shooter (new as in competition shooter, have lots of rounds downrange recreationally).

Best,

Brad

[Nathanb]

As someone who will be tackling this very shortly thank you

[MemphisMechanic]

2 hours ago, ryridesmotox said:

Good writeup

One note on the disassembly instructions in post 2. 

When I did my fitting, I fit the safety bar to the sear. The sear is cheaper to replace, but you also have to remove it from the cage several times, each time more annoying than the last. 

Info fixed in #2.

Fitting the safety to the sear is also an effective way to go. And faster.

[MemphisMechanic]

2 hours ago, Bapple said:

Think I am gonna give it a try and do this myself after seeing your thread.  Thanks for the tutorial and info, much appreciated.  

Brad

The best part about the sear-fitting? Once you pull the sear housing out to do it, the rest of the inner workings will be wide open to see.

These guns aren't nearly as complex as they look.

Take your time. Polish all the pins and holes and springs. It'll reward you with the smoothest trigger you've ever pulled. The springs set your pull weight, polishing determines its smoothness.

[MemphisMechanic]

46 minutes ago, Nathanb said:

As someone who will be tackling this very shortly thank you

That's why I did it! This badly needed resource is missing.

It took me the better part of a whole morning to write and edit the description of a process I can accomplish in 10 minutes.

[johnbu]

Good write up. Nice clear pictures and description will REALLY help a lot of people.  you 'da man!

 

It was a pleasure discussing these guns with you. But, seriously... dirty up that gun.  All that cleanliness is making my guns feel bad!  lol.

[MemphisMechanic]

17 minutes ago, johnbu said:

Good write up. Nice clear pictures and description will REALLY help a lot of people.  you 'da man!

 

It was a pleasure discussing these guns with you. But, seriously... dirty up that gun.  All that cleanliness is making my guns feel bad!  lol.

Thanks John! I'll probably pester you again in the future.

It'll stay fairly clean as I keep an eye on things like the FPB operation. Once I'm satisfied I'll tear it down and cerakote it. Then all bets are off.

It'll be cleaned every few thousand rounds whether it needs it or not. 

[MemphisMechanic]

4 hours ago, Bapple said:

Hope to get this done myself soon, as there is a club USPSA match nearby in 2 weeks and I hope to make it my first match.

I'm going to suggest (to avoid cluttering a "how to" post and keep it on topic) that you take a look at the BEginners forum or post this content in a similar group where you'll be getting answers from more than just those of us who shoot Tanfos.

[highhope]

Great, thanks man...

[billthemarine2862]

This is a great write up.  I know I had to look in a few different places (and still posted forum questions). When doing my install.

Very impressed with the dremel work fitting the sear and safety.

i didn't have the guts to use the Dremel when I fit my xtreme sear..  It took me about 15 fittings to hand file it.  I read a post from Johnbu in a thread about the Titan hammer where he talked about hand fitting his sear. I figured he has forgotten more about working on a Tanfo than I know about one so I did it that way.

 

Edited November 18, 2016 by billthemarine2862
Content

[MemphisMechanic]

If you actually watch the factory sear & safety operate you'll see that the place you're fitting things is actually not super-precise.

I felt just fine dremeling that particular spot, and it's the only place in the gun that's still rough and unpolished: I didn't particularly care if application of the safety was a bit gritty, and it turns out to be imperceptible anyway.

[billthemarine2862]

When I build my next one I will certainly go with the Dremel.

Is that just a nail holding your sear in place while you are using the dremel?

Edited November 18, 2016 by billthemarine2862

[MemphisMechanic]

25 minutes ago, billthemarine2862 said:

When I build my next one I will certainly go with the Dremel.

Is that just a nail holding your sear in place while you are using the dremel?

When I actually removed metal I was holding it by hand.

To prop the sear up for the photo, I slid it onto a punch sticking out of my "armorers 2x4" 

There's no need to do so unless you need a third hand to snap a picture.