Safety Selector Issues: A Geometrical Mini Adventure

Today we're going to be sharing about safety selector issues and a problem that stumped us for a couple days. It also involves a short geometric adventure so sit tight.

A few customers came to us with a rather unusual issue - after installing their Hammerheads, tightening the set screws, and installing the safety selector switch, it seemed that the trigger would still fire while the selector indicator was set to safe. Could this be an issue with the safety tang at the back of our Hammerheads? Could this be an issue with the selector switch? Could this be an issue with how the lower compartment was originally cut?

What we found were largely two reasons. First, the selector switch installed was faulty or below the normal variance for thickness. The selector simply wasn't catching the safety tang on the back of the trigger group. This can be tested by trying out a few other triggers and seeing if the selector issue persists. If other triggers don't work- then its probably a selector issue and not a trigger issue.

Second, was a much more subtle issue involving transversals (a line that passes through two lines in the same plane at two distinct points) and Euclid's parallel postulate:


If a line segment intersects two straight lines forming two interior angles on the same side that sum to less than two right angles, then the two lines, if extended indefinitely, meet on that side on which the angles sum to less than two right angles.


Whew, that's a mouthful. How this applies to the situation is that some Hammerheads arrive with the set screws already protruding. Customers will drop the trigger in with the protruding screws and insert pins without issue. Even though the trigger is tilting backwards just a little, pins are still insertable due to Euclid's parallel postulate - the two lines extending across the pin holes of the trigger compartment are still parallel, so the pins can still be inserted even though the trigger is no longer parallel to the lower compartment. Following instructions customers will tighten the already protruding set screws to prevent any reset misfires, but thereby further extending the screws and cause the trigger to tilt backwards just a little bit more.

All this tilting back results in an issue: the safety tang on the back of the trigger is now angled downwards, so when the safety selector is switched to safe it no longer touches the safety tang - allowing the trigger to fire.

So how do we solve this issue? The process is quite straightforward:

  1. Take the trigger out of the compartment
  2. Using the allen wrench ensure the set screws are fully withdrawn and not protruding. You can eyeball the trigger from the side view to see if the set screws are still sticking out.
  3. Now place the trigger back into the compartment and it should be completely level.
  4. Insert pins
  5. Insert safety selector, test that it is functioning by engaging the hammer, placing the selector to safe and attempting to pull the trigger. If the trigger no longer fires, congrats we solved the issue, but there are still a few more steps.
  6. Disengage the hammer if you have not already done so.
  7. Now attempt to perform a reset misfire by engaging the hammer while holding down the trigger. When releasing the trigger the hammer should still remain engaged, if the hammer releases as well then we move on to the next steps. 
  8. To solve the reset misfire issue, take the allen wrench and tighten (turning clockwise) the set screws until you can't anymore. This means the set screws are now pushing against the pins and bottom of the compartment to fully secure the trigger. When the trigger is fully secure the mechanism can perform correctly and prevent a reset misfire
  9. Repeat test on 7)

Whew if you got this far, congrats! As always for any questions and concerns send us a message at the contact us page. Stay frosty.