Short recoil operation captured just before the base of the bullet clears the muzzle.
Clicky. Embiggen.
Clicky. Embiggen.
A Thousand Words.
- Thread starter John Travis
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Great picture. I see the barrel is still locked into the slide. I also see that the slide/barrel unit has already started its rearward movement before the bullet has left the barrel judging by the relative positions of the end of the barrel and the end of the guide rod.
you are right, but i think you missed something crucial.
I probably did. What did I miss?
I did notice the reference grids attached to the frame and slide after I posted. That certainly allows for better quantification of movement.
Both the barrel and slide moved. They were locked up?
Nope. Note all the combustion gas ahead of the bullet when the base isn’t out of the barrel.
OP
Yep. Barrel and slide are locked horizontally and move together for .200 inch of rearward travel until the link or cam has completely disengaged the barrel vertically.
Yes.
That always happens. There are any number of slow motion videos that show gases escaping ahead of the bullet. Interestingly, lead bullets show less gas escape due to earlier obturation, provided the bullet isn't too hard, which accounts for typically higher velocities with identical bullet weights and powder charges.
It's probably metric...2.54 mm converts to 1/10th inch...assuming a 5-inch barrel, 230 grains of bullet at around 830 fps. It will vary with different bullet mass and velocity. For instance, calculations show that a 9mm 1911 firing a 124 grain bullet at 1150 fps mv gives a slide travel at exit of right around .070 inch.
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A perfectly cromulent word.
Agreed
OP
As it must.
I only wish I'd had that photograph 20 years ago. It would have saved reams of typing and countless arguments trying to explain it to people who insist that recoil doesn't start and the slide doesn't move until after the bullet exits because Jerry Kuhnhausen said so...which would defy the laws of physics.
It’s a very patient equal and opposite reaction…
Does this mean that all of my missed shots are my fault?
The recoil didn’t make me miss 😂?
The recoil didn’t make me miss 😂?
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Wonder why that is a hard concept for people to follow? Even without that photograph, I always thought recoil starts immediately after the powder ignites. I understand that the slide has more mass and must also overcome the recoil springs tension, so it would be moving slower than the projectile. But would start at the same time. If that makes any sense, I’m not good with the scientific jargon.
I always heard some argument that the friction of the bullet traveling forward against the lands and grooves of the rifling would “pull” against the force of recoil, keeping the pistol in battery until the bullet exited the muzzle.
But that always seemed nonsensical. If everything remained locked up until the bullet exited the muzzle, what active force would remain in the system to start rearward motion of the slide after the bullet was free? Uncontained exploding gasses? The momentum of the empty case?
The only way it works logically is if the fast light bullet and the slow heavy slide start moving apart the instance things start exploding.
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OP
That is correct. The bullet's forward drag acts to resist the slide's movement rearward. It actually offers the largest resistive force in the system, which explains why the gun can be fired without a recoil spring with no adverse effects.
It's very simple. Whatever frictional resistance the barrel places on the bullet, the bullet places on the barrel...and whatever resists the barrel's rearward movement resists the slide's.
I get the concept of friction, but my amazement was always the statement that friction alone would prevent rearward motion of the slide outright. The force imparted through drag would have to be nearly equal to the portion of the explosive forces acting on the slide.
OP
Not in firing normally, no.
Several years ago, I decided to find out how much resistive force the bullet placed on the barrel by using a steel rod to push a bullet from chamber to muzzle on a bathroom scale.
It required 103 pounds to start it, and 94 pounds to keep it moving.
That level is more than all the other factors of recoil and mainspring, hammer mass, slide and barrel mass, and slide to frame friction combined.