Bump on Trigger Bar

Discussion in 'General Glocking' started by Xandrosi, Jul 15, 2016.

  1. shawn mccarver

    shawn mccarver

    Messages:
    1,870
    Likes Received:
    2,683
    Joined:
    Dec 14, 2008
    Personally, I trust the factory engineers and gun designers more, MUCH MORE, than some person with enough time on his hands to make these amateurish videos.

    Don't polish or grind off bumps intentionally put there by Glock as part of the design of the pistol.
     
  2. harold63

    harold63 I'm not retired

    Messages:
    6,968
    Likes Received:
    3,474
    Joined:
    Nov 25, 2014
    Location:
    SW Florida
    I notice these threads on the 'bump' get smaller and smaller. Maybe those are figuring out the bump really isn't a big deal. I'm very critical. If it was making a difference, I would say it. FWIW.
     

  3. MoRivera

    MoRivera

    Messages:
    1,966
    Likes Received:
    872
    Joined:
    Jun 21, 2015
    It makes a small difference...I guess the question is: is it enough to matter?
     
  4. harold63

    harold63 I'm not retired

    Messages:
    6,968
    Likes Received:
    3,474
    Joined:
    Nov 25, 2014
    Location:
    SW Florida
    I use 1000, 1200, and 1500 grit wet dry paper, depending on how rough the surface is, to do my trigger polishes. I finish, of course, with compound and glaze, to get that 'brilliant' shine. I never even messed with the bump until that was done on prolly 5 or 6 of my Glocks, and that was due to reading my first 'bump' thread, here. Pull weights, after I polished everything, with all out of the box parts, averaged 4lbs, 10 to 12 ozs, before I polished the bumps in those guns (these Glocks came with 4.5 connectors and are Gen 4's). The pull weights stayed the same. Not only that, when I put grease on the slide where that bump rides, the bump literally was barely touching the slide. The grease trail was minute. I would like to reverse a mag catch on one and do a 'lefty' to see what the pull weights are. I have no idea 'cause I've never shot a 'lefty' Glock. My guess, just by looking at everything, is it can be tuned to also barely touch the slide while it does what it is designed to do.
     
  5. MoRivera

    MoRivera

    Messages:
    1,966
    Likes Received:
    872
    Joined:
    Jun 21, 2015
    As I tried to illustrate earlier, it's not an issue of the bump rubbing the slide and causing friction, but it causing the rear of the trigger bar...the 'blade'...to push in more on the connector (which has a slight outward angle), via leverage. In the second video you can see how the bar moves slightly outwards at the end of the pull/trigger break with the Gen 3 bar, but not with the Gen 4. So I don't think it's a pull weight thing as much as it is a little stiffer feel before break.
     
  6. RPMSTL

    RPMSTL

    Messages:
    782
    Likes Received:
    787
    Joined:
    Apr 7, 2015
    I have used both Gen 3 and 4 bars on the same G4 pistol many times. The Gen 3 trigger bar results in a smoother trigger. After thousands and thousands of rounds, no negative affect has been noticed by switching a Gen 3 bar into a G4 frame.
     
  7. harold63

    harold63 I'm not retired

    Messages:
    6,968
    Likes Received:
    3,474
    Joined:
    Nov 25, 2014
    Location:
    SW Florida
    I get that. I don't believe the bump is pushing the trigger bar over. Matter of fact, I know it doesn't. That resistance you're speaking of has to do with the angle of the connector.
     
  8. Rusty Guns

    Rusty Guns

    Messages:
    2,780
    Likes Received:
    1,831
    Joined:
    Oct 22, 2005
    Location:
    Deep In SC
    Now Now You Kids Play Nice!! :cheers::cowboy::fred:
     
  9. MoRivera

    MoRivera

    Messages:
    1,966
    Likes Received:
    872
    Joined:
    Jun 21, 2015
    Well, the actual thing is, I know it is, and I've witnessed and repeated it on my own between a Gen 3 and 4 bar in the same gun. You can see the movement in one and not the other. And when compared side-by-side, there is no angle of difference between Gen 3 and 4 trigger housings and connectors...much like in the first video. So it's clearly the bump, but not in the way that many may think.

    It's not so much 'pushing the trigger bar over', as it is keeping it from pushing out with the connector's outward angle. It's small, but it is there. Not trying to be argumentative, but it is indeed a fact that it's there...and I had to really compare to be sure. Again, some may notice it...and care...more than others. And if not, all the better...one less thing to concern oneself about.
     
    Last edited: Jul 20, 2016
  10. glock11

    glock11

    Messages:
    66
    Likes Received:
    16
    Joined:
    Jul 9, 2008
  11. MoRivera

    MoRivera

    Messages:
    1,966
    Likes Received:
    872
    Joined:
    Jun 21, 2015
    I did too...I, unknowingly, got a gen 3 smooth-faced trigger and bar to replace the serrated-face one in my gen 4 g26. I immediately noticed a little difference (not huge) which I would describe as a little less stacking/hitching as it approached the break. Later realized that I had a gen 3 bar in. Tried the original gen 4 bar in a gen 3 G19 and it felt a bit stiffer like the G26 did at first. Interestingly, the sideways movement of the trigger bar that I mentioned earlier is more noticeable on the G19 than the G26, end coincidentally so it the felt difference in trigger pull. Neither with the gen 4 bar was unshootable or unpleasant. Frankly if i didn't have them side to side for comparison, I'd be fine with the gen 4's.....especially for carry.
     
    Last edited: Jul 20, 2016
  12. Mr Meeseeks

    Mr Meeseeks

    Messages:
    4,799
    Likes Received:
    9,564
    Joined:
    Nov 18, 2017
    Gravedigging a thread instead of starting a new one. I understand why the bump was added to all Gen 4 pistols.

    What I don’t understand is why the bump was necessary on all Large Frame pistols and GAP pistols. I know the Firing Pin Safety on these is larger. I assume the bump was required to keep the TWTB mechanically centered with the FPS. Why?

    An ancillary question, what would happen if one used a ‘bumpless’ TWTB (part #357) in a G37. More specifically a G37 NOT intended for use as a serious weapon, but only for fun and games.