1st round from mag always low, 4+1 syndrome

[GLOOB]

deleted

 

[barnbwt]

"The prevailing theory, the last time I did any reading on it, had to do with how the first round was being chambered and how releasing the slide from slidelock had a different dynamic of forces, on barrel lockup, than when the slide was driven to the rear of it's travel by the recoil of the preceding shot."

I have to wonder...if the pressure of a full-er mag on the underside of the slide might have something to do with this. It doesn't make intuitive sense how dropping from the slide lock vs. the violence of a firing cycle would consistently produce two separate lockups, unless the former was not strong enough to force the action into battery completely (doubtful).

Another factor that may or may not weigh in could have something to do with hot powder gases left inside the barrel after the first shot, similar to how suppressors' effectiveness changes abruptly after the cold shot.

Lastly, I hate to say this, it could be completely shooter-induced. First shot occurs right after the stabilizing thumb has wiggled around, and the first shot "seats" the gun completely in the palm, subtly changing the impact of even the most consistent shooter. Might even be a touch of anticipation/flinch that is ordinarily compensated for consistently, but that is nonetheless different on that first shot of a set, again, even for the most practiced shooter.

TCB

 

[MachIVshooter]

Lastly, I hate to say this, it could be completely shooter-induced. First shot occurs right after the stabilizing thumb has wiggled around, and the first shot "seats" the gun completely in the palm, subtly changing the impact of even the most consistent shooter. Might even be a touch of anticipation/flinch that is ordinarily compensated for consistently, but that is nonetheless different on that first shot of a set, again, even for the most practiced shooter.

Pretty much summarizes my thoughts on this phenomenon.

 

[ATLDave]

^^ Yep, me too. I accept that it's theoretically possible that some lockup (or other internal-to-the-gun) issue is driving this phenomenon, but human factors seem by far the simplest explanation.