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Discussion Starter · #1 ·
I have been working on my Sig Match Elite 9mm. After setting the trigger bow forward stop position slightly past the reset point (adjusting the "wings" on the front of trigger bow), the plunger lift (upper) lever tip is sitting slightly high above the frame (the forward-most position of the trigger bow back surface has been moved slightly rearward), so the slide will not pass over the upper lever tip on reassembly. For now, I just moved the forward trigger stop position a bit forward to lower the upper lever tip until the slide clears it. In shooting this gun (at my level) I don't even notice this, but if I were to want to further fine tune, please look at the following.

Question: It would be possible to remove a little material from the front face of the lower lever where the trigger bow contacts, or from the back of the trigger bow where the lever contacts. However, either will reduce the distance of upward travel of the firing pin (FP) stop plunger with the default lower and upper lever geometry. This could prevent the stop plunger from clearing the firing pin, disabling the gun. It is hard to determine how much additional travel there is past blocking the FP at the point the sear breaks. Have any of you done this type of tuning that can comment on a course of action? It may be possible to slightly alter the engagement geometry between the upper and lower lever to increase the lift height relative to the trigger travel, but this is getting a little into the weeds for what I want to experiment with, without some additional knowledge. The alternative would be to modify the clearance groove in the FP stop plunger to clear the FP a little earlier, but I do not presently have a lathe (on my wish list) and that would be necessary to fit the FP stop plunger that way.

Thanks for any information you may have.
 

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Pre-travel is needed for the 1911, first hold the trigger back, force the muzzle back just enough to force the hammer back to half cock, release the slide, release the trigger, and check that it did re-set. Or you can simply pull the hammer back to half cock and check if the trigger is tight, or as it should has a slight amount of slack.

In regards to the S80, cock hammer, engage the thumb safety, pull trigger back and hold, check that the firing pin is free from the block.

LOG
 

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Discussion Starter · #5 ·
Pre-travel is needed for the 1911, first hold the trigger back, force the muzzle back just enough to force the hammer back to half cock, release the slide, release the trigger, and check that it did re-set. Or you can simply pull the hammer back to half cock and check if the trigger is tight, or as it should has a slight amount of slack.

In regards to the S80, cock hammer, engage the thumb safety, pull trigger back and hold, check that the firing pin block is free.

LOG
Thanks for you info. I understand the firing and safety systems geometry and how to function-check all aspects. The issue here is the need to remove material at one of a few places to alter the geometry/relationship of the trigger bow, lower lever, upper lever, and stop plunger. The relative distances are small, so doing this by trial and error could take a bunch of iterations with very small removal increments. Once you go the slightest bit too far (too much material removal) the firing pin block plunger will no longer allow the firing pin to slide forward. Then you are buying more parts and starting over. I would like to avoid that without some idea of how much material can be safely removed to lower the upper lever tip, without casing the lever not to lift the plunger enough by the time the sear disengages the hammer.

I think I'll investigate the Strike Industries grip safety-actuated FP block system. My Kimber 1911 Stainless II uses this configuration.
 

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A properly-working 80-type safety is a beautiful thing. You do need to check it regularly to make sure the timing is right and the pin is not getting beat up by the plunger. I don't think your Sig is going to be 'Elite' very much longer.
 

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Thanks for you info. I understand the firing and safety systems geometry and how to function-check all aspects. The issue here is the need to remove material at one of a few places to alter the geometry/relationship of the trigger bow, lower lever, upper lever, and stop plunger. The relative distances are small, so doing this by trial and error could take a bunch of iterations with very small removal increments. Once you go the slightest bit too far (too much material removal) the firing pin block plunger will no longer allow the firing pin to slide forward. Then you are buying more parts and starting over. I would like to avoid that without some idea of how much material can be safely removed to lower the upper lever tip, without casing the lever not to lift the plunger enough by the time the sear disengages the hammer.

I think I'll investigate the Strike Industries grip safety-actuated FP block system. My Kimber 1911 Stainless II uses this configuration.
Before removing any material, check the pre-travel as described. The risk is if too little pre-travel the sear can not fully engage the half cock notch and why the trigger may be tight when the hammer is pulled to half cock. Try it. Also setting the pre-travel as close as you describe can result in trigger bounce hammer follow. To check cock hammer lock the slide back, and with the frame griped holding the grip safety in, hard drop the slide.

LOG
 
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