As a great musician once said, rust never sleeps. Well, neither do we here at TTAG. Always looking for new and innovative ways to serve, entertain and inform the Armed Intelligentsia, we’ve been experimenting with slow motion videography. Fun? You betcha! Difficult? Nah, more of a steep learning curve. Baby steps, though…baby steps. Here are a few of our first attempts for your dining and dancing pleasure. We have more work to do before adding this particular tune to our extensive and growing repertoire, but let us know if you have any bright ideas for how you’d like to see it used in new and innovative ways. Above is a Smith & Wesson Model 28 Highway Patrolman firing a .38 spcl. Make the jump for a couple of 1911 vids…
Be patient. The fun starts at about 0:23 on this one:
And thanks very much for all the cooperation we got facility-wise from our friends at Top Gun Shooting Sports in beautiful downtown Arnold, MO, just a hop, skip and a jump south of St. Louis.
Wow. That was all Matrixey and everything.
You guys should start with a look over all of the various action types. Browning Auto 5s look great under slow motion. Long recoil action.
Coooooool! But you’ve created a monster. (“What started as a 5 second b&w slow-mo in 2011 has now become the world’s most………”)
High-speed film is always fascinating.
Okay, you guys are the AI, so I have a question for you: why is there a delay in recoil until after the bullet exits the barrel? Who can explain the physics of this in terms a dumb artist can understand?
Ditto. But for a dumb anthropology student.
Because until the bullet leaves the barrel, there is no “action” (gases exiting the barrel) to cause a “reaction” (recoil). Thats also why there is usually no recoil on a “squib” round. Not enough pressure to get the bullet to leave the muzzle and not enough gas pressure to cause gas ventage and recoil. At least, thats how I understand Newtons Law
Actually, I’m not sure I buy that. There are expanding gases acting on the breechface as well as the bullet before the bullet leaves the barrel. Energy is being imparted to the slide as soon as the charge ignites.
I think the real reason is that the slide is freely traveling to the rear until the recoil spring tunnel hits the guide rod and stops the slide’s travel. The slide’s momentum is then transferred to the frame and the shooter’s hand. If you watch the first video closely, you’ll see that the shooter’s hand really starts to move only when the slide comes to a stop.
In other words, the recoil is immediate. It just doesn’t translate into vertical movement until the slide has finished its rearward travel.
This doesn’t explain the same phenomenon in revolvers.
That’s true. As Nick mentions below, the bullet’s pull on the barrel is a significant factor. I guess my eyes aren’t fast enough to notice the lack of recoil in these videos between hammer drop and the bullet leaving the barrel. The lack of jump while the slide is in motion is way more noticeable to me.
The 1911 forum had a great thread exploring exactly these physics a while back. It’s long but really informative.
http://bit.ly/itbwPh
It’s got to do with the forces acting on the barrel. While the bullet is in the barrel, the forces on the gun are balanced due to the friction and the movement of the bullet. But once the bullet leaves, the balance shifts dramatically in one direction.
If you’re really interested in the physics, I can do a write-up with all sorts of graphs and stuff…
Heck yes!
I would say that recoil begins the instant the round is fired. Due to the weight of the slide and and recoil springs compared to the weight of the bullet, the slide moves slower than the bullet. Therefore the bullet leaves the barrel before the inertia of the much heavier slide is overcome.
Do I win a prize?
Traditionally, recoil is regarded in two stages, primary and secondary. Recoil begins the instant the bullet starts moving, in accordance with Newton’s third law. There is a force pushing the bullet down the barrel, so there is an equal and opposite force pushing the weapon in the other direction. Momentum is conserved. That’s primary recoil.
When the bullet departs from the muzzle, secondary recoil begins. As the bullet clears the muzzle, hot expanding gases follow behind it. At this point you might visualize the barrel and muzzle and the escaping gases as a rocket engine, producing the secondary recoil, which typically is longer in duration and of greater magnitude than the primary recoil.
Wouldn’t the secondary recoil be nullified by a suppressor?
My idea is that it works like Newton’s Cradle. The energy is transferred rearward from the cartridge to the slide or frame of the gun and continues until it transfers to the hand, resulting in muzzle flip. The time from the ignition to the transfer to the hand is just enough for the bullet to clear the barrel, at least in a semi-auto.
looking at revolvers in slo-mo, the muzzle seem to be rising a little before the bullet exits. This might explain why lighter loads shoot lower than heavier ones: the heavier bullet would take slightly longer to exit, so the barrel would be slightly inclined.
I know, it’s silly of me to speculate. I can’t help it, I’m part nerd.
“Wouldn’t the secondary recoil be nullified by a suppressor?”
In some cases, yes.
As the poster above you explains, primary recoil is basically the firearm and you moving backward as a reaction to *just* the bullet moving in the opposite direction, and secondary recoil is experienced when the over-pressure inside the barrel is released by the bullet leaving the barrel.
With the proper suppressor, and other parts, it is possible to reduce felt recoil by slowing down and cooling the gasses — effectively, you’re expanding the time over which the event occurs, as well as reducing the overall space the propellant gasses take up (this is basic physics — PV = NRT and similar).
Thus, with the proper suppressor setup, you can significantly reduce the speed at which gas is exhausted from the muzzle, as well as preventing the action from cycling (assuming a semi-auto).
Brilliant! By the way – down’t you have Luger/Parabellum somewhere around, for a chance? 🙂
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