Currently Your Best Sig 556 Trigger Option | SIG Sauer 556 Forum

Currently Your Best Sig 556 Trigger Option

Discussion in 'The Machine Shop' started by texas gun smith, Jul 2, 2017.

  1. texas gun smith

    texas gun smith Active Member

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    I'm not currently doing this type of work atm, maybe later as I get things squared away. But I get requests from time to time on various platforms. I plan on directing those requests to this link to save me typing time, lol.

    I have always thought the Sig 556 triggers suffered from 3 problems. 1.)Pull weight, horrid 2.) Pretravel, annoying 3.) overtravel

    What I can tell you is the new style Shooting Sight trigger works for removing the felt pretravel, I felt it myself, its good. It works. A while back, I helped a guy with the latest gen Shooting Sight, and implemented some of my own to go with it. Works perfect.Took A bunch of pics was trying to document it, but time is an SOB these days.

    Shooting Sight earlier generations did not remove pretravel from what I know. As he's a bit paranoid I guess, he adds a bunch of legal mumbo jumbo and such to his package, in it he sayes not mess with the trigger in any way, including things I know that work, and if i've read it right, not to install his own trigger, which is truly funny imo. He's just protecting himself is my guess.

    Anyway his latest gen now remove felt pretravel. The parts are nice and high quality. You remove stamped metal, mim, and plastic parts, and install nice machined parts. It does not reduce pull weight or overtravel however. Not to worry as these are easily fixxed, though against his packages warnings to do so. Again, the same package that expressly says not to use an aftermarket trigger. The only oddity to his trigger is the slot for disconnector spring. Slot is quite wide with new parts. Spring can go in cattywompus initially this way. If unnoticed, maybe an issue. During install use a baby screw driver to get spring straight. Once straight, and pieces together, it will remain straight. You may also double the disconnector, with one inside the other, I forget, read instructions and figure it out.

    Your own mod to either original trigger, or Shooting Sight:

    Note: Stock trigger vs Shooitng Sight trigger. The hammer breaks at slightly different spot depending which you use. So a different thickness spacer will be needed for one or the other in the following mod.

    One of worst parts of the Sig 556 trigger is pull weight imo. To fix it is easy to do by yourself. Add a spacer to the bolt behind trigger. That spacer will cut your pull weight in half. Make the thickness of spacer so that hammer breaks every time just prior to trigger touching that bolt. This will eliminate overtravel as well.

    Inside the grip is a nut and spring on that bolt. Remove grip. Take nut and spring off, need 7mm and 5.5mm wrench. Put spacer on bolt head side. Tighten bolt so that the bolt head moves up against that portion by pistol grip. In this way trigger will no longer touch it when you pull trigger. This effects actual trigger parts in NO way, but with that stupid bolt not pushing on trigger as you pull trigger, you get about a 4.5lb pull, nice.

    Use #8x32 brass machine screw nut or washers for your spacers. Could be #10x32 I forget. Any lowes or home depot has them in hardware section in little plastic bags for $2. If so inclined, make nuts thinner with a file or grinder, if you are handy you can round the points off as well so that you have a circle spacer. I think I ran a 1/8" drill through the center of mine, but you can figure that out if it needs it. Before taking your stuff apart, turn gun sideways and lay your spacer parts on shaft of tiny bolt. Make sure gun is clear. pull trigger slowly with washers/nut laying on tiny bolt to see if and where hammer breaks. You want it to break just before bolt has squished the washers/nut tight against pistol grip. Leave room for reliablility's sake, In that i mean hammer breaks just prior to bolt being up tight, not as it gets perfectly tight. You want slight overtravel,let's say .010"-.020", not zero overtravel. No overtravel can occasionally lead to pulling trigger but no boom. When you figure out the right spacer thickness, paint them black. Install. done. 4.5lb pull.

    Stock trigger vs shooting sight trigger will require different thickness spacer, his breaks at slightly different spot than stock trigger from what I saw.

    When I was in the midst of doing these a made a youtube series on it that you may find useful as I show complete trigger disassembly and assembly, as well as the spacer mod from above. Ignore the crossbar portion as that is now solved with current gen Shooting Sight trigger:
    SIG 556 Trigger Enhancement Series - YouTube
     
    Last edited: Jul 2, 2017
  2. PGT

    PGT Member

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    ShootingSight has 10% off right now. Sort of a no-brainer
     
  3. aj3501

    aj3501 New Member

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    I tweaked your instructions slightly. all I removed was the pistol grip. after that I backed the stud all the way out so it touched the trigger. then I used #6 brass spacers/washers and I cut the spacer and twisted it so that I could get it around the bolt. once around the bolt I flattened the spacer back out. i added spacers until most of the over travel was removed. I left some as Texas Gun Smith advised doing. Once you have the over travel mostly removed just tighten the nut back up and you are done. took me all of 15-20mins. i did not have to add any spacers on the inside before the nut, but you may have to.
     
  4. Bosley

    Bosley Active Member

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    IIRC one of the 'bolts' that are the overtravel stop on one of mine are bent, but I did manage to get it locked in at just the right place.

    What I'd do is buy a swiss lower and swap out the internals as I don't see how that trigger can be improved. I think they are excellent triggers.
     

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