my M40-A1 does not consistently reset trigger when dry fire

Discussion in 'M, C, L and S Series' started by alex, Oct 1, 2007.

  1. alex

    alex Guest

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    I went to the range yesterday and fired 50 rounds without a single problem. Came home stripped the gun down to five components: slide, barrel, recoil spring, magazine, and the frame. Cleaned and oiled every parts and put them back together. Then I realized the trigger didn't reset every time I rack the slide back and forth to practice dry fire. Sometimes I had to rack the slide back and forth about four to five times in order to reset the trigger. Prior to yesterday I was able to reset the trigger each and everytime by pulling the slide back just 3/4 of an inch to do dry fire. Now it is a hit and miss thing sometimes the trigger reset with an inch pull back of the slide sometimes it required four to five racking of the slide all the way to the back in order to reset trigger. Also the pressure of the trigger pull seemed to vary. Do I have a broken gun?
     
  2. Wulf

    Wulf Premium Member

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    Hi alex :)

    I always rack my slide to its fullest then let 'er buck! :) I never did the "only rack it back a bit and check the trigger reset thing" before. <shrug> Maybe someone else more in tune with the M and S Series trigger reset function will reply to your post, PDQ. Just out of curiosity, what happens if ya just rack it back to its full rack and let 'er slam home? :shock: Does it reset ever'time? :shock: Mine does. <shrug>

    Wulf
     

  3. ThaiBoxer

    ThaiBoxer Active Member

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    Doesn't sound good. Both mine reset with slight draw backward. Already break it down and reassemble to make sure something is not goofy?

    Ben
     
  4. bigtaco

    bigtaco Active Member

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    i have to believe that if cleaning caused the problem, cleaning can cure the problem.

    remove the sub-frame from the grip and thoroughly soak it under hot running water to flush away all the loose grit. the hose it down with your favorite solvent.

    run it under the hot water again to get the solvent out.

    hose it down with lube of choice and blow the lube out with compressed air/canned air.

    re-assemble and try again.

    should clear it up.

    let us know
     
  5. alex

    alex Guest

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    I have heard about the possible gummy stuffs that got into the firing pin channel and caused the trigger reset problem. I did a very thorough cleaning. I dis-assembled the gun into five major parts then I soaked everything in two gallons of MPro-7 solution sold by Midway for about an hour before I brushed clean every surface. I paid very good attention to the slide particularly the firing pin area. I didn't dis-assembled the slide because I couldn't quite follow the instructioin in this forum. After the cleaning I swang the slide many times to get rid of all the cleaning solution. I then sprayed Dura-Lube into the firing pin channel until it was dripping wet. I waited a little for the lube to penetrate the all the unreachable areas then I swang the slide many times to remove any excess lube. I then re-assembled the five components together. Wipe down the outside then I realized the trigger did not reset. I pulled the slide all the back and let it slam forward and the trigger reset. If I just rack the slide an inch backward the trigger would not reliably reset everytime. Prior to this deep cleaning there was not one trigger reset problem. This morning (after two days) the gun seemed to work fine by itself. Once again I was able to rack the slide slowly back an inch and ride it forward slowly and the trigger reset everytime. Strange? I wonder if the trigger catch (if there is such a thing) was too oily so it wasn't holding. However after two days most the excess oil drip away and the trigger catch has some resistence to work with. Does it sound logical?
     
  6. bigtaco

    bigtaco Active Member

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    hmmm. strange.

    one of the things to be careful of with the steyr is OVER lubing the firing pin channel. you say that you shook the lube out, but i would go even farther and use a q-tip the remove all the lube except a slight film.

    as far as what you've done and what you've described, nothing is jumping out at me without taking a look at it.

    a quick check is to pop the slide off and push down on the sear/catch (triangle part). it should pop back up. if it's getting stuck in the down position, this can cause trouble. best to get this corrected by SAI/ steyr mannlicher.
     
  7. alex

    alex Guest

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    I removed the slide and pressed onto the sear/catch. It went down very little and popped back up. Also I could see the sear moved slightly when I pull the trigger. It has been six days since I deep cleaned the gun and she is working correctly now. I can do dry fire and the trigger resets OK.
    While the slide was out of the gun I discovered that the firing pin was not under any spring tension. In fact I could move the firing pin back and forth about 2 or 3 mm. There is free play for the firing pin when the slide is out of the gun. Is that normal?
     
  8. tlrpunk

    tlrpunk New Member

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    Mine does the same thing, I believe it is normal.
     
  9. heavymetalmachine

    heavymetalmachine New Member

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    Hey BT mine stays down until I move the trigger.. What kind problems will this cause???
     
  10. yugo308guy

    yugo308guy Member

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    One thing I've noticed while dry firing any of my Steyrs is that if you don't keep the trigger fully to the rear while you are racking the slide, there is a problem with the trigger resetting. I have never had a trigger reset problem as long as I conciously keep the trigger all the way back. If you let up slightly wjile you are racking the slide, the trigger will not reset until you let it travel fully foward and then pull it.
     
  11. alex

    alex Guest

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    True. I found that out yesterday. I went to the range and again gave the gun a deep cleaning. After I re-assembled the gun and it couldn't reliably reset trigger everytime when I rack the slide back. Then for some reason I was holding the trigger all the way back and rack the slide at the same time the trigger reset everytime. Not that my gun couldn't reset trigger all the time when dry fire it just not 100%. With the trigger pull all the way either holding it there or let go then racking the slide back will reset thr trigger 100% of the time.

    So after all the trigger reset thing was really an operator error, my error.
     
  12. madecov

    madecov Active Member

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    Mine has this very occasional issue.
    I find that aggressively wracking the slide hard the gun will re set.

    I've never had an issue under recoil.
     
  13. bigtaco

    bigtaco Active Member

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    heavy metal machine: the sear "catches" the firing pin tang as the gun comes into battery.

    if you push the sear down and it stays down, this isn't a guarenteed problem as the trigger will reset as long as the sear is on top of the post.

    however, the sear sticking down when it is behind the post can cause the infamous steyr doubling.

    the causes can include: dirt... seriously! goopy gritty dirt. or... casting lines left on the side of the sear, casting lines in the frame, or a slight curvature in the punched drop safety.

    i wouldnt worry about it if you're not experiencing problems. the day that you do have trouble, SAI will take care of you.

    also,

    your trigger should reset regardless of where your finger is during recoil.

    a slow trigger pull resulting in a true surprise break does not include remembering to keep the trigger fully rearward during slide cycling.

    there are two causes for your trigger not to reset unless it is held fully rearward:

    1) improperly bent trigger bar is impeding the up/down and forward/back motion of the sear.

    2) the front of the sear has scratched a groove in the face of your post. the groove momentarily grabs the front of the sear which holds it down and allows the firing pin to get ahead of the sear during return to battery.

    the fix is easy enough. pull your trigger bar and ensure that the bend in the bar after it passes the magazine area is exactly 90 degrees.

    inspect the face of your post to ensure that there is no scratch. if there's a scratch, use some 1000 grit on a mirror to polish the face smooth and inspect the front of the sear for the burr which was causing the scratch.


    BUT... BUT... we have SAI now!! yeah!! go steyroids!!! SO... in the unlikely event that your gun actually malfunctions in any way, those great guys can diagnose and repair anything that's causing trouble and get it back to you lickety split!!!
     
  14. heavymetalmachine

    heavymetalmachine New Member

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    Thanks bt !!!!!

    I had done some**tinkering** over the weekend and got it worked out.

    Thanks again!!
     
  15. pilotbenjamin

    pilotbenjamin New Member

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    what did you do? because my m40 sometimes doesn't reset? I've tried everything. short of sending it in. I just hate to be without it.
     
  16. alex

    alex Guest

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    Holding the trigger all the way back when racking the slide to do dry firing when reset the trigger every time.
    During actual firing there should be no trigger reset problem. Otherwise your gun needs to see a doctor, SAI.