What causes recoil and noise

JOERM · Nov 11, 2011

This is a new one for me. Yesterday I sold a few Winchesters at a guys house who buys an sells guns. Good guy and knows a lot. He sales 50 guns a month on guns brokers. Here's the deal. I had a model 97 pump with a strange choke on it. He checked it out and all that and could not figure out how it came to be and what not. He's a winchester nut and knows his stuff.

Then he said this: "the recoil and sound is caused from the vacuum in the barrel when the air is sucked back in after the shot." or something like that. In other words, the "kick" was not from the powder going off, it was from the vacuum caused from the bullet going out the end of the barrel and air slamming back in. along with the sound barrier being broke or what ever.

Have any of you heard of this before?? I may not have explained it just like he said it but you get the drift.

Joe

A10 · Nov 11, 2011

I think the guy has been following horses around and collecting the residue to share with his customers. Recoil is a manifestation of one of Newtons laws. Every action has an equal and opposite reaction. The amount of recoil you feel is subjective, everyone has their own sense of it and people who shoot alot seem to be less sensitive to it.

Alk8944 · Nov 11, 2011

In short, he's full of ****! Ask him if he has ever heard of Newton!

ContinentalOp · Nov 11, 2011

Firing a cartridge is basically setting off an explosion. The rapid expansion of gases produces positive overpressure and is the source of the "bang." This positive overpressure displaces air. If the explosion is strong enough the air displacement creates a void that is filled with air rushing back towards the source of the explosion; this is negative pressure or negative overpressure.

However, the negative pressure is much lower than the postive overpressure. I'd hazard a guess that firing a small arms cartridge is going to create minimal, if any, negative pressure. It's just not a strong enough explosion.

As for recoil, that's simple physics. "For every action there is an equal but opposite reaction." When the gun fires, the explosion pushes the bullet out the barrel. But the bullet also pushes back against the gun. The force generated is equal in both directions, but because the gun is so much heavier than the bullet it travels much slower and we perceive that velocity as recoil.

Confused yet?

RYNO · Nov 11, 2011

Not. With that line of 'logic' a gun with a snub barrel would have less recoil than a longer barrel, wouldn't it?

Iggy · Nov 11, 2011

I always figgered it was pulling the trigger.....

quneur · Nov 12, 2011

Recoil is a change in momentum. Through Newton's second law, momentum must be conserved. So, recoil = Fprojectile - Fpowder conversion. There's many factors involved, mass of the gun, speed rate of the powder burn, etc.

Loudness is pressure of the powder explosion (burn). Sound is air pressure. For calibers (like shotguns) which are slower than the speed of sound (1087 ft/s), sound differently - subsonic then those calibers that are supersonic. Doppler effects come into play or 'sonic booms' like jet aircraft. The additive effects of the initial explosion + doppler effects will sound louder and hurt your ear more. That's why a supersonic round will 'crack' vs 'boom' of a subsonic round.

AKAOV1MAN · Nov 12, 2011

I am not sure that there is any underpressure at all when a small arm is fired. The expanding gases take up all the space in the barrel behind the projectile, and equalize when the projectile is expelled from the barrel leaving expanding gasses behind. When the gas is totally gone from the barrel I am not sure it leaves a vacum. I know that really big arty pieces do so, but they are on a high order of really big barrels-the 120mm gun on the M1A1 tank is an example. The big guns on a battleship need to have the gas blown out of the tube before reloading, but a small arm? Maybe, but at a very low order.

OFT II · Nov 12, 2011

I would love to hear his theory on how an internal combustion engine operates.

Bell Charter Oak Holsters · Nov 12, 2011

What causes recoil and noise?

Chili, onions, sauerkraut, peas, beans, beer and just about anything else you eat after age 50!

Cheers;
Lefty

sipowicz · Nov 12, 2011

Let's just hope he doesn't have to explain sex to his kids...

1 old 0311 · Nov 12, 2011

Alk8944 said:
In short, he's full of ****! Ask him if he has ever heard of Newton!

Isn't he the guy who invented the FIG Newton?

Rule3 · Nov 12, 2011

1 old 0311 said:
Isn't he the guy who invented the FIG Newton?

Eat enough of those and there will be noise and explosions also.

fiasconva · Nov 12, 2011

Wow, and I thought all this time it was caused by pulling the trigger.

ChattanoogaPhil · Nov 12, 2011

Recoil and noise?

I have no idea what you're talking about.

Uploaded with ImageShack.us

jkc · Nov 12, 2011

I'd have had to ask, "Who are you, so wise in the ways of science?"

bobelk99 · Nov 12, 2011

JOERM said:
This is a new one for me. Yesterday I sold a few Winchesters at a guys house who buys an sells guns. Good guy and knows a lot. He sales 50 guns a month on guns brokers. Here's the deal. I had a model 97 pump with a strange choke on it. He checked it out and all that and could not figure out how it came to be and what not. He's a winchester nut and knows his stuff.

Then he said this: "the recoil and sound is caused from the vacuum in the barrel when the air is sucked back in after the shot." or something like that. In other words, the "kick" was not from the powder going off, it was from the vacuum caused from the bullet going out the end of the barrel and air slamming back in. along with the sound barrier being broke or what ever.

Have any of you heard of this before?? I may not have explained it just like he said it but you get the drift.

Joe

I call B. S.

Too bad we don't have a BS flag.

TACC1 · Nov 12, 2011

Combustion engine??

OFT II said:
I would love to hear his theory on how an internal combustion engine operates.

That's easy; Suck, Squeeze, Pop, Phooey.....
What else you want to know?
TACC1

pilgrim6a · Nov 12, 2011

A little knowledge is a dangerous thing. That fellow is very safety minded.

HighPowerShooter · Nov 13, 2011

oldflatfoot said:
Chili, onions, sauerkraut, peas, beans, beer and just about anything else you eat after age 50!

Cheers;
Lefty

that and lipitor!

What causes recoil and noise

Member

Member

US Veteran

Member

Member

Member

Member

US Veteran

US Veteran

Member

Member

Member

Member

Member

Member

Member

Member

US Veteran

Member

Member

Similar threads