I will read up on this. Thinking back on it, I shot my two S&W 29's, one with 6" barrel and one with 10 5/8" barrel, and I don't remember the length of the barrel causing me to shoot higher? Maybe that's not a fair comparison, but I also had a Model 41 with both a short and long barrel. There was never a noticeable difference in the height of the group as I switched barrels, and shot at different distances.
Somewhere there was a detailed explanation of what happens when a bullet is fired, and I thought I remember reading that the bullet is out of the gun before the gun reacts. Unless the gun is clamped in a "vice", it seems like it would move straight back first, and then when there is resistance from the shooter's hand, it would move upwards.
More research to do......
Mike,
That's a good video. Play it back and at the 10 second point pause it. The bullet has not left the barrel at that point but note what is happening at the breech. There is a discharge of gases and powder residue coming from the breech. This means that the gases from the burning powder have pushed back against the breech. The propellant is moving the bullet forward and obviously recoil has begun. The burning powder produces gases, as we know, and that gas expands at the same rate in all directions, but having really only two ways to go, forward and rearward, it pushes the bullet forward.
How can I say that "obviously recoil has begun" when it doesn't look like the slide has moved at all till later? Because the gases that propel the bullet push the case against the breech face to push the bullet forward. It's this that causes recoil. The gun is designed as a delayed recoil arm which means that the bullet will not leave the barrel before the slide unlocks, but
obviously not before recoil begins.
Heavier, slower bullets, all thing being equal, strike higher on the target because they take more time in the barrel. This is generally true. But it is less true in semis due to the action of the slide which absorbs a good deal of the impulse of the recoil. The recoil spring, powder and load all play a factor. It's more visible with a wheelgun.
You mention that you did not notice a bullet striking higher on a target from a 6" barrel rather than a 10 5/8" barrel gun both guns M29s. I assume also the same weight bullets. You won't, especially if both guns are sighted to place the same weight bullet in the same spot at 25 or 50 meters. But take one of those guns and sight it in for a bullet weighing 180 grs at the same distances, say 25 or 50 meters, and shoot enough to get a decent group. Now without changing the sights load a 240 gr. bullet, aim and fire. It should, all things being equal, hit higher.
Play around with this some.
Robert Rinker, "Understanding Firearm Ballistics" Chapter 22.
Thank you for the advice on flinching and anticipating the shot. I got over any physical flinch that I may have had from being anxious about the actual firing process, back in 1973 when I fired a 1911 for the first time. Maybe earlier as a child with my father but I don't recall that. But from then till now I still fight pushing into the shot, my form of anticipating it, sometimes I win and sometimes not. I'm worse at it when tired or impatient.