Stock 2 SA hammer not falling

[MilkMyDuds]

New Stock 2 in the hands of a newbie.

Did first round of polishing of contact areas, and installed Extreme FP and hammer springs (light), Titan hammer, Extreme firing pin and Wolff recoil spring. Went to range 200 rounds 100% ignition with WSP without any problems. I was really happy with the reliability but not so with the 8 lbs DA and 4 lbs SA pull.

So last night I took the sear apart in an attempt to polish more. It was a 2-piece sear, and I had a lot of trouble to put it back together, because atlas 101 guide shows a different 2-piece sear than the Tanfo's. With the help of some friend's picture of their sear in Stock 2, I put it back together.

However, since then I found that the DA hammer would work fine but hammer won't fall for SA. I can see the top of the sear moving when I press SA but hammer not moving.

I suspect I did something wrong to the sear when I put it back together. Here are some pics of how my sear block look like. Do they look right to you? If the sear looks good, maybe I polished too much on the trigger bar or bottom of sear?

Should I guy the Extreme sear housing and Extreme 1 piece sear? Maybe they will fix the problem?

Thanks for helping.

[MilkMyDuds]

Here is the DA trigger pull working fine:

http://www.youtube.com/watch?v=ht0F77S-SDQ

[MilkMyDuds]

Here is when SA pull does not move the hammer at all:

http://www.youtube.com/watch?v=hZhZb--m880

[fellas]

First off the spring of the sear should be down in that slot, did you screw in the trigger screw too far?

another thing could be when installing the extreme firing pin , you need as well to install the extreme firing pin safety

http://www.ericgrauffelonlineshop.com/en/upper-parts/345-firing-pin-safety.html

Edited March 14, 2016 by fellas

[MilkMyDuds]

First off the spring of the sear should be down in that slot, did you screw in the trigger screw too far?

another thing could be when installing the extreme firing pin , you need as well to install the extreme firing pin safety

http://www.ericgrauffelonlineshop.com/en/upper-parts/345-firing-pin-safety.html

Yes I have the Extreme firing pin safety and spring I did not put on the upper parts for this testing. Is it needed for testing trigger? I will try that.

[MilkMyDuds]

First off the spring of the sear should be down in that slot, did you screw in the trigger screw too far?

another thing could be when installing the extreme firing pin , you need as well to install the extreme firing pin safety

http://www.ericgrauffelonlineshop.com/en/upper-parts/345-firing-pin-safety.html

Trigger screw - I think CZs have a screw there, but for Tanfos it's just a plunger. I don't think one can insert it too far deep in the hole because the bottom of the hole is frame.

[EngineerEli]

I think he is talking about the over travel screw on the trigger. If that is screwed in too far, it can definitely keep the hammer from dropping in SA. It would be possible for the hammer to still drop in DA depending on the fitment of the disco. I would back out the over travel screw on the trigger a bunch and test again. I like to have the screw in about a 1/4 turn less than it takes to feel contact between the hammer and sear when holding the trigger all the way back and manually pulling and releasing the hammer. Contact here may still allow proper function, but can cause your hammer or sear to wear out faster...

[MilkMyDuds]

I just took another video.

I can make the SA hammer fall, but I need to push down the trigger bar, while holding it down, squeeze the trigger and hold the trigger. Then I slowly let go of the trigger until I hear 1 click, then press trigger and SA hammer would fall. If I wait for the 2nd click while letting go of the trigger (there would be a total of 2 clicks), then SA hammer would still not fall.

Is it possible I polished the trigger bar too much where it contacts the sear?

http://www.youtube.com/watch?v=hgEgsI9iCEw&feature=youtu.be

[MilkMyDuds]

I think he is talking about the over travel screw on the trigger. If that is screwed in too far, it can definitely keep the hammer from dropping in SA. It would be possible for the hammer to still drop in DA depending on the fitment of the disco. I would back out the over travel screw on the trigger a bunch and test again. I like to have the screw in about a 1/4 turn less than it takes to feel contact between the hammer and sear when holding the trigger all the way back and manually pulling and releasing the hammer. Contact here may still allow proper function, but can cause your hammer or sear to wear out faster...

I looked at the over travel screw, it is already backed out as much it can, to a point where further backing out would stick the back of that screw out of the trigger surface.

Besides, I had the gun working perfect condition Saturday morning. I have not touched over travel screw.

[johnbu]

The sear assembly would be my guess mostly because you just messed with it and struggled. The large part of it (that holds the hammer back) doesn't seem to be moving enough. I'd take it apart, watch a few more (different) videos and assemble it again. Ill root around in the box of pulled "junk" for an old 2 piece and see if that's it.

oh, try not to worry too much, I've had plenty of fubar moments like this and it's usually pretty easy to correct once the understanding of the problem is found.

Edited March 14, 2016 by johnbu

[MilkMyDuds]

The sear assembly would be my guess mostly because you just messed with it and struggled. The large part of it (that holds the hammer back) doesn't seem to be moving enough. I'd take it apart, watch a few more (different) videos and assemble it again. Ill root around in the box of pulled "junk" for an old 2 piece and see if that's it.

oh, try not to worry too much, I've had plenty of fubar moments like this and it's usually pretty easy to correct once the understanding of the problem is found.

Thanks.

I almost bought the Extreme complete sear block to save the struggle and trouble but I have a Limited Pro incoming today so I can take that sear block and put it in this Stock 2 see if it's truly the sear issue. If it's the sear, I probably would go Extreme.

BTW - what's the DA/SA pull like if I swap in all Extreme parts, e.g. complete sear block, trigger bar, disconnector, trigger bar plunger, etc. with other parts polished? It may actually be worth the cost if it can do 6lbs DA and 3lbs SA.

[fellas]

http://www.interforzebrescia.it/index.php?option=com_kunena&Itemid=91&func=view&catid=12&id=650&limit=10&limitstart=310

here are some picture of the proper way the 2 piece sear should be mounted , the language is Italian but with the pics you should work

Edited March 14, 2016 by fellas

[johnbu]

The lim pro will have a one piece sear, but not chromed. Geometrically the same just different finish (at least that's what I think)

Got distracted dry firing and forgot to look for the 2 piece.

If you go full extreme with polishing, you would still need to weaken the trigger return spring slightly. (I use a propane torch to just barely relax the set. But it's way easy to f up and have a too weak spring that won't reset. I did two to get one and I worry it may fail having been weakened). Also would need a cz sear spring which is lighter. Then experiment with various springs hammer/fire pin with cutting coils. Some well respected folks reported cutting the end tight wrapped coil off the 14# is best. I never tried that.

My opinion is that a smooth reliable 7# trigger is better than a finicky 6# trigger. Chasing low numbers has turned into a death spiral of wasted efforts and expense more than once. But, I'm no where near a good enough shooter to truely benefit from wringing out those last oz of trigger pull. Heck, I doubt it would impact me much going from 7 to 9#.

It's fun to tinker, but frustrating when you improve parts until they fail. Have fun.

On edit, I must have either given away, tossed or "stored someplace safe" my 2 piece sears because I could not locate them. Sorry!

Edited March 14, 2016 by johnbu

[MilkMyDuds]

I finally figured out what's wrong. It makes me look stupid, I know.

What happened is that I put on the CGW floating trigger pin for easy swapping in/out parts to test the triggers. I have it there all the time...

Now I put in the real trigger pin, DA/SA works flawlessly!

Thanks for everyone's input and pointers. DIY gunsmithing obviously requires more than just being handy

[johnbu]

Good job!

For me, diy gunsmithing just took not knowing the task was too hard or maybe being too stubborn to stop? Dunno, but persistence and attention to detail have been helpful.

[eboadway]

I've used the CGW pin, and now the Canik variant, and don't see how the pin would cause the problem. Maybe something else changed during disassembly/assembly?

Edited March 14, 2016 by eboadway

[MilkMyDuds]

I've used the CGW pin, and now the Canik variant, and don't see how the pin would cause the problem. Maybe something else changed during disassembly/assembly?

It's a bit odd I know but swapping the pin is the only change. I put on the CGW floating pin, or used a 1/16 punch in place, SA won't fall. I switch back to factory pin, everything works.

The CGW floating pin is much smaller in diameter than the factory, very similar to 1/16 punch.

Sent from my GT-N7105 using Tapatalk

[johnbu]

Obviously some aspect of the geometric tolerance stackup gets out of whack when the smaller pin is put in there. Maybe someone with a good understanfing can figure out why, but it's sure not the expected source of that failure.

[EngineerEli]

If you were using the CZ CGW pin it does make sense. The smaller dia pin allows your trigger to pivot at an axis slightly further forward, so even once you pull the trigger to the over travel stop, the part of the trigger that pushes your trigger bar rearward, is still slightly further forward than it would with the larger pin. Glad you got it figured out. Now just go out and get the floating pin for the Canik and you'll be all set! That is what I use, personally after polishing the pin, I think it smooths things out slightly over the factory roll pin.