I was recently working on a problem with a V2 build that really had me baffled. I thought I tried everything and couldn't figure it out.
The problem was the gun would release the striker on reset. So, rack the slide, pull the trigger - it fires. Hold the trigger back, re-rack - then just when releasing pressure for reset, the striker fires. But sometimes, the trigger wouldn't reset, it would just stay back.
I swapped everything short of the frame. Sometimes it was better, sometimes not.
Anyway, I reached out to Johnny Glocks and he directed me to one of his videos - Your Gun means your responsibility.
In the video, he identifies 3 things that cause this "engagement" issue.
Backplate
Slide to frame relationship (sloppy slide)
Cruciform engagement
He also stressed that when testing for safety, ALWAYS do it with a magazine inserted. (Yeah, I knew that but wasn't consistently doing it).
It turns out I had all 3 problems with this build.
I wasn't paying close enough attention, and didn't realize I had a non-OEM backplate on the gun, when I didn't have the Armorer's backplate on. Replacing it with an OEM backplate fixed about 50% of the problems. Actually, I didn't realize how many problems it was introducing that I just thought were quirks, or related to the "real" problem.
Look at the photo. OEM is on the left. The "depression" for the spacer sleeve on the non-OEM backplate is bigger and deeper than the OEM plate. There is no "finger" in the depression to keep the spacer sleeve from twisting (due to torque from the spring). Also, the "foot" on the right side in the picture is wider than the OEM plate. Finally, on the OEM plate, the center "foot" is beveled, the non-OEM isn't.
When I really looked at slide sloppiness, I realized it was actually pretty bad. So, I tightened up the slide until I just had a little bit of wiggle. Probably took out about 75% of the slop. I thought this fixed the problem because it functioned perfectly. UNTIL I put in a magazine. Then it would fire on reset almost every time.
So, although I had decent sear engagement, I tweaked the cruciform until I had 100%+ engagement. That fixed it completely and it passes all safety checks, racking, smacking, and dropping.
I learned a lot on this one!
Where did you get the back plate?
Great Info thanks