I also feel its a combination of things either together or independent, heavy pull, gritty pull, still pulling after the sear has released, flinching ( can send them anywhere ) or jerking downward, all are especially worse the smaller the gun.
This is why so many people are much more accurate with a decent S/A type trigger or triggers like the XD and Glock.
Because I was shooting back in the day, I cut my teeth on revolvers because reliable semi's using hollow point ammo were not abundant outside of some 1911's or browning Hi-power's. I got used to and was conditioned to the D/A action due to the revolver being the gun of the time. Today many shooters rarely train on or even have a true D/A weapon.
I think in a true life and death situation most people might be better off with a XD type trigger as long as the pull isn't too light. Adrenaline has a way of lightening triggers up even more so. I feel it takes more focus to shoot a D/A accurately especially under stress, and many can't or don't dedicate the trigger time to be proficient.
The real danger to America is not abroad but within..
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Save America, abort liberalism.