Striker to 'sear' fit? Something isn't right.

Discussion in 'Gunsmithing' started by bczrx, Aug 30, 2015.

  1. bczrx

    bczrx

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    I just picked up a lightly used G30SF today. So lightly used there are no barrel wear marks from firing, even though it was bought in 2012.

    As I disassembled and inspected it, prior to any range time, I noticed something that made me want to grab my arkansas stones. Before I did, I thought I'd check with the Glock experts though, as I am relatively new to Glocks.

    It is evident from the wear marks on the striker's 'foot' and the rear of the cruciform ['sear' edge], that the striker is held by about 1/3 to 1/4 of the sear, on one side of the mating area.

    My first instinct is to begin using Dykum Blue to chart wear and start to lightly dress down the face of the cruciform's 'sear' area, until I get 'full engagement'.

    What I mean by 'full engagement' is that the wear marks should be uniformly spread across the face of both the striker's foot and the sear.

    Does this sound like I am on the right track?

    I AM experienced in sear/hammer, or in trigger/hammer [where appropriate] fitting, with successful results on 5 1911s [3 I have built up from frames and parts], 4 BHP, 7 different revolvers, 4 different rifles, 3 Ruger MK II or MK II 22/45s, miscellaneous other handguns and a couple of shotguns. This is a reference to sears I've stoned to change the characteristics. It doesn't include work that required no work on my part on the sear/striker or sear/hammer interface. I've also prepped the surfaces on my AA upper for my G22, and fit other parts. I am not bragging. I am identifying my skill level when I am proposing this solution. No one on here knows me personally, so none of you know what I am aware of, or what I have successfully done in the past. This way you have a better idea of what to suggest to me.

    I don't like working on the cruciform/sear edge, as it is so thin that holding the same angle is a challenge. I'd rather work on the striker itself. However, I was always taught to work on the cheapest replaceable part first, and the trigger/bar/cruciform sear are all less than $20, while strikers seem to be closer to $50.

    Does my process sound right, or am I missing something?

    Thanks!
     
  2. Dave.1

    Dave.1

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    Seems like someone may have worked on the cruciform already. Generally you want about 2/3 engagement on the cruciform, not less.
    [​IMG]

    No matter what skill level we're talking about, I think I'd start with a new trigger bar and then see where the lug on the firing pin hits the end of the cruciform. If you feel it's not engaging properly on the new part, then bring in the Dykum Blue.

    Dave
     
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  3. bczrx

    bczrx

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    Thanks,

    Just so you know, the 1/3-1/4 engagement I am referring to is the fact that it only engages on the far right corner of the contact area. I wasn't referring to engagement like a 1911, where you have about .020 of contact, but it is spread along the entire width of the contact area.

    I'll give it a whirl.
     
  4. Dave.1

    Dave.1

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    Yeah, I got that part about the engagement area, bczrx, That's why I was wondering if some one had taken a stone to the end of the cruciform.

    How much material would you have to take off to bring the engagement back to center? I guess that would determine whether I got a new trigger bar or not.

    Dave
     
  5. bczrx

    bczrx

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    I don't know how much needs to be removed yet. Looking at it without my magnification visor on, it looks pretty even.

    I don't see obvious stoning [or, shudder, filing] marks on it. I will try to lightly dress it down first, before moving to a new part.

    I guess the pieces of info I don't have and thought would be relevant are:

    Are these trigger bars [sear area primarily] surface hardened? Or are they a constant hardness, like tool steel?

    Secondly, is there any surface coating that I would be removing and might result in higher incidents of rust?

    Thanks,

    Jason
     
  6. Dave.1

    Dave.1

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    My experience is that the cruciform is a constant hardness.

    The parts are coated, as I recall. I think it's a very thin electro plate, so will wear in time. I've had the plating wear off of the firing pin stop and never had an issue with corrosion.

    Dave
     
  7. bczrx

    bczrx

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    Cool,

    Thanks. That takes away concerns about why I shouldn't stone the sear area. I will break out the dykum blue and stone sets!

    My wife rolls her eyes, as I have yet to find a gun with a trigger I didn't want to 'fix'.
     
  8. Dave.1

    Dave.1

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    Part of the enjoyment of owning a pistol is getting it set up how you want it.

    Dave
     
  9. bczrx

    bczrx

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    True. So true.

    Sent from my SM-G900P using Tapatalk
     
  10. TN.Frank

    TN.Frank "Don't Tread On Me!"

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    I had something striker/cruciform related happen this morning when I took the G19 out to test fire it.
    I installed the smooth face trigger and 3.5# Lone Wolf connector that I had in my G26 into the gun and polished the sear of the striker with some 1000 grit emery cloth. Same things I've done to my G37(except for the smooth trigger), G38 and G39. When I fired the first shot another shot broke as I was resetting the trigger. I gave it another try and got two rounds off with the reset. I unloaded the gun and though WTF. I went ahead and dialed in my ARs that I'd brought with me then figured I'd do a little test. I pulled the Striker Assembly out of my G37 that I had with me and installed it into the G19 and it worked as per normal, no more multi-shots so I figured it may need a new striker.
    After I got home I took a flashlight and watched the striker/cruciform action and also watched it on the reset and sure enough, the cruciform wasn't engaging the striker enough to hold it during reset to it was slipping off and causing another round to fire.
    I put the stock trigger and 5# connector back into the gun and watched the action again and this time all went well.
    Not sure where to go from here, new striker and re-install the smooth trigger and 3.5# connector or just leave it like it is or what?
    How would I fix it so the smooth trigger would work properly with the stock striker, do you bend it up slightly for more contact or what?
    I'd like this gun working 100% with the lighter connector(doubt that was the issue anyway) and the smooth trigger if I can.
     
  11. Dave.1

    Dave.1

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    Hi TN.Frank. Without seeing the cruciform on the smooth face trigger, I'd have to guess that the section you polished with the emery cloth may have gotten rounded top to bottom so it's not catching the lug on the firing pin with a full flat face. You may be able to mark the rear of the cruciform face with a sharpie, re assemble and see where the firing pin lug is engaging.

    Dave
     
  12. TN.Frank

    TN.Frank "Don't Tread On Me!"

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    The crazy thing is that this Trigger Assembly worked flawlessly in my Glock G26. and when I changed out the striker assembly from y G37 into the G19 it also worked flawlessly. I just wonder if it's something to do with tolerance stacking between the stock striker in the G19 and the smooth trigger/trigger bar that makes it not engage enough.
    Can you slightly bend the cruciform so it engages more of the striker sear? I made a slide cover plate out of one of my unused stock ones so I can see the engagement better like the orange ones they want $4 bucks for.
     
  13. Dave.1

    Dave.1

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    You could be right about the tolerances of the parts.

    As far as bending the cruciform, I've heard of people doing that to fine tune their Glocks but I've got now experience doing it. Maybe someone else will spot this and chime in.

    Dave
     
  14. TN.Frank

    TN.Frank "Don't Tread On Me!"

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    I've just NEVER had an issue like this with any Glock I've owned. I've dropped in smooth triggers and 3.5# Lone Wolf connectors in quite a few Glocks and polished up the sear face on the striker with all of them and I've always been careful to not change any angles or take off too much. Just a little polishing with some 1000 grit emery cloth.
    I think I may try to slightly bend the cruciform a bit to get better engagement and see if I can get that smooth trigger installed.
     
  15. bczrx

    bczrx

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    You may be right about tolerance stacking. I can't tell without inspecting what you see.
    I think Dave.1 has the most likely diagnosis.

    Have you ever worked on sears before? I mean, polishing [with stones], cutting, adjusting: not swapping out parts. Also, did you use a perfectly even rod on the other side of the emery cloth when polishing, or did you use your finger? I've botched a few sears with fingers and emery cloth [or 1500grit sandpaper too].

    I ask about the experience with sears as one thing that amazed me was that the sear/hammer connection is as little as .030 or so on most 1911s, carried cocked and locked.

    For comparison, I would guess that the thickness of the cruciform is closer to .125.

    I have not used armorer's end plates to inspect multiple Glock handguns. Others may have, and they can address my following thought.

    My thought is that you did round the top edge, as Dave.1 suggested. And the other element is my thought that the entire thickness of the cruciform is not in constant contact with the bottom of the striker sear. I

    I am purely guessing here, transferring knowledge from other devices, that an inspection of many Glocks would show that half the height of the cruciform was engaged normally-not the entire amount. If that is what you are noticing in the first place, you may not have anything to worry about other than the rounding/cut of the sear face.

    I could EASILY be wrong, and others who DO know, please chime in to correct me. I want to know this also.

    One last point about your attempted solution of bending the cruciform up.

    I don't see how you can bend that rear end of the cruciform up to engage the striker more without changing the geometry of engagement. Once this is changed, you will need to cut the sear at a revised angle to make it align with the 'factory' angle. This requires stones, not cloth.

    First, I would inspect the trigger bar/cruciform under a magnifying glass to see if it is rounded.

    If it is, I would invest in some fine arkansas stones for gunsmithing. The 1/4 x 3" is about right for this job, and MidwayUsa has them. I would use this and lock the trigger bar into a vise to keep it immobilized, and then I would cut an even cut on the sear at the same angle. Once it is even and no rounding occurs, this should fix the issue, as long as you haven't added a connector with an overtravel stop. that may need to be adjusted now.

    Good luck.

    Experienced Glocker, please correct my misunderstandings. Don't let him follow what should work on many other guns if you know it doesn't work on Glocks!
     
  16. TN.Frank

    TN.Frank "Don't Tread On Me!"

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    I've done quite a few successful trigger jobs on both 1911a1s and S&W Revolvers without any issues. I've never had an issue with any of my Glocks and I've owned quite a few of em' and given them all the .25 cent trigger jobs and LW connectors. I made a slide cover plate out of an unused factory plate and gave the sear/striker engagement a look. With the factor trigger it was about 2/3rds if not a touch more but with the smooth trigger it was less then 1/2. I used a small crescent wrench to bend the sear on the trigger bar up slightly and then re-installed the smooth trigger and now it's 2/3rds or a bit more and doesn't slip off on reset. I think it will be fine now but I'm not going to chamber a round in the gun until I get a chance to get out and put a few rounds through it.
    Just for grins I checked my G38 which also has a smooth trigger installed and it's 2/3rds and good. I still want to give my G39 a look because I've also installed a smooth trigger in it but it hasn't doubled or done anything strange so I'd bet that it'll be fine and of course the G37 came from the factory with a smooth trigger so I don't expect anything to be off with it.
    I always wrap the emery paper around something flat so I'll keep the angles correct. I've done my own gunsmithing for probably 30+ years and I've also worked as a Machinist. One job was making fuel injector nozzles for the 777 where tolerances were .0002"+/- and yes, you read that right, Two Tenths of a Thousands so I know a bit about maintaining tolerances.
     
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  17. bczrx

    bczrx

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    Cool! I don't know anyone yet, so I apologize if I erred on the side of underestimating you. It looks like I can learn a lot from you! :yourock:

    Thanks for the details. That also helps me to understand these pistols. I'm glad it has a strong engagement.

    Any sign of roll-off or creep in the trigger break with a snap cap? I still haven't decided if I like a rolling break on 1911s or a crisp glass-rod break. That applies to other guns also. I think I prefer the crisp one, but find the rolling break on my Ruger P97 makes it hard for me to flinch in anticipation, and my groups are tighter than they should be.

    Keep us posted about your findings please, inquiring minds want to know how it goes!
     
  18. mtstream

    mtstream

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    Check the amount of engagement with a stock connector in the gun before giving up on the trigger bar. I've seen a number of people have double fires with Ghost connectors recently. I can only theorize that there's something about the connector not allowing the trigger bar to fully return before engaging the firing pin lug. I would not have suspected the connector before but in both cases the problem went away when the connector was changed. Another point to check is that the drop safety area of the trigger housing is smooth (nothing for the trigger bar to catch on when trying to return).

    If that doesn't solve it, replace the trigger bar. If it's clearly an issue of engagement being too low you can bend the cruciform up but being that it's already been modified (even if done correctly) I'd be a little hesitant to keep messing with it. - oops, missed that you said you'd already bent it up. It should be OK, but I'd only load 2-3 rounds per mag for awhile when testing.

    I think it's important to keep a mental picture of what's happening in the pistol when working on them. Glock's trigger bar actually acts upon the firing pin by pushing it back before releasing. A sear on 1911's ect. hold the hammer. Splitting hairs, I know but I hope you'll think about that process when making decisions about modifying. For what it's worth, Glock doesn't use the term sear :)
     
  19. mtstream

    mtstream

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    With Glocks, the connector makes the difference in the feel of a crisp break or softer. The standard or dot connectors will have a much crisper break than a minus connector or the lighter weight aftermarket connectors. It has to do with the angle on the connector that interacts with the trigger bar. The steeper angle of the standard/dot results in a harder wall and crisp break. The lesser angle of the lighter connectors smooths this interaction out which results in a lighter but slightly more sluggish feel.
     
  20. TN.Frank

    TN.Frank "Don't Tread On Me!"

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    Ditto and the more shallow angle of the "-" connectors also results in less force to pull the trigger but as you said, it's slower to let off of the striker so it's more, for lack of a better term, "mushy" as opposed to the flat angle of the standard connector which drops the cruciform off of the striker faster for a more crisp break.