event chain

[fasteddieG]

I wonder if anyone knows the actual sequence of events when a recoil operated gun like the 1911 is fired. Is the projectile clear of the muzzle before the action begins to unlock and open? I reload and I was thinking about headspace and cartride length considerations and began thinking about what happens first. visualizing the primer explosion and the powder igniting & burning & the gas expanding and the projectile overcoming inertia as it begins to race out the barrel to exit the muzzle. At some point the slide begins to travel in the opposite direction disengaging from battery and doing it's job of extraction, ejection, picking up the fresh round chambering & coming back to battery. Considering that the slide weighs far more than the projectile one supposes that the time required to overcome inertia is longer for the slide than the bullet response time but it also seems that the realitive movement would begin at the same time with the barrel and slide moving together at first and the toggle link drawing the barrel down and out of battery untill the barrel is fully disengaged and the slide continues through the remainder of the cycle. If the projectile was not clear of the muzzle the action/reaction would have a proportional effect on accuracy. this would tend to cause vertical stringing of shot groups which (perhaps coincidentily) is what I see most at the range.

 

[the naked prophet]

The barrel/slide are locked together and move as one unit until they are unlocked. The instant that the bullet starts to move, the slide/barrel starts to move. Physics. The bullet moves much faster due to its lower mass.

At the instant that the bullet leaves the barrel, the slide/barrel assembly is moving straight backwards, and is moving at the maximum speed. It is entirely the momentum of the slide at this point that finishes the entire operation of the gun. So the bullet has gone, and the slide/barrel are moving backward very fast.

At about 1/8 inch of travel, the barrel is cammed downwards and unlocks. The hammer is also being pushed backward by the slide at this point.

When it has unlocked, the barrel stops moving but the slide continues backwards, extracting the case and compressing the recoil spring. The slide continues to cock the hammer.

The slide continues rearward with the case attached under the extractor until the case hits the ejector, at which point the case is knocked through the ejection port. The hammer has been fully cocked and is now riding under the slide.

The slide compresses the recoil spring fully, stopping at the rear of its travel.

The spring then pushes the slide forward again. The slide travels forward, pushing a round out of the mag and into the barrel.

The slide meets the barrel as it continues forward, and pushes the barrel forwards. As the barrel is pushed forwards it is cammed upwards to lock up with the slide.

Once the barrel and slide are locked together, they move forwards another 1/8 inch or so and reach the forward most point. The pistol is now in battery and is ready to fire again.

 

[fasteddieG]

That all sounds reasonable and is clearly correct except for the statement that the slide & barrel are locked together untill they are unlocked. Also obviously true except that the nature of the toggle link who's motion is radial must begin to move in the vertical plane the instant that it begins to move rearward. After traveling that 1/8" rearward it has traveled probably 1/16" downward at which point it is fully disengaged and then continues rearward doing all the things you listed. Once the slide/ barrel begins to move rearward the barrel must begin moving downward (physics) at the link end. the amount that it moves downward as it moves rearward may be miniscule but it is not none so the time it takes for the projectile to exit the barrel is a factor. A very short link coupled to a very long barrel would illustrate my point. I don't doubt that there is negligable movement just as the initial radialialy motivated vertical movement appears negligable as compared to the longitudinal movement. If the differences in velocity were sufficient you could say that the angular displacement of the barrel realative to the slide was miniscule or negligible but you can't say none. I think.