why there is a ridge on the striker spring guide rod?

Discussion in 'Maintenance / Tweaks / Technical Difficulties / So' started by alex, Nov 10, 2007.

  1. alex

    alex Guest

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    I noticed that there is a ridge on the striker spring guide rod where the trigger weight sits. Why is it necessary to have that ridge there? As the striker being compressed the trigger weight needs to slide down on the guide rod. It seems to me that the ridge might cause initial resistence where the trigger weight might get caught on there and therefore inconsistent trigger pull. I am so tempted to grind away the ridge and make the guide rod smooth.
    Of course before I do that I want to check with you guys who know the Steyr better.
     
  2. bigtaco

    bigtaco Active Member

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    EXCELLENT QUESTION!!!!!!!!!!!!

    KUDOS!!!!!!

    i'm no steyr armorer or firearms designer nor authority on steyrs or anything, so i shoot from the hip based on years of being around machines in general.


    accepting that the trigger system in the steyr demands that the weight be allowed to travel fully to the end of the guide rod... this little undercut ensures that any crud (such as powder residue combined with lube) has a place to go and will not impede the weight moving fully forward on the guide rod.

    imagine having the spring and weight fully compressed. now coat the guide rod with crud, when you release the spring/weight, the weight will push this crud to the end of the rod and the weight will not reach the end. this will leave the spring under extra tension, therefore creating additional preload on the striker.

    i believe that the steyr design is principally based on providing the maximum allowable amount of preload that will NOT detonate a primer.

    by making this slight undercut, it is ensured that the spring will remain at it's intended amount of preload even with a little extra lube and powder residue. it also keeps the crud from scratching the guide rod.

    that being said, the firing pin guide rod CAN BE a source of friction. polishing the guide rod is a good way to smooth trigger feel as is polishing the internal surfaces of the weight.

    to polish to the extent that no ridge remains would be bad in many ways for many reasons. you'd be removing a LOT of material from the guide rod. never a good idea. the weight would then be a very sloppy fit on the rod which is bad for trigger feel. you'd then have to squeeze the weight SOOOO much that it would no longer be round. bad again.

    so... a light polishing of the rod focusing on smoothing the material that is there and maintaining the excellently machined shape of the rod is your best bet.