Does this sound right to anyone?

wayupnorth said:
one of my kids is doing a course via distance ED to get a couple extra credits and the course they picked up was a forensic's course.
(kinda wish they had those when i was in school - looks neat!)

so i was walking by and she asked me a question.....
which gun has more kinetic energy, a revolver or a pistol?

i stop, look at her and say.... a revolver is a pistol.

she shows me her module and it shows a 'pistol' as a semi auto pistol.
so im like.... errrr ok.

ill let that pass i guess, seems like a silly mistake.
so then she says, never mind, i found the answer in the readings, the semi auto has more kinetic energy.
i was surprised by that.
my thinking was the revolver would have more because the semi auto uses some of the gases to do its blow back where the revolver does not.
but the reading module states that revolvers are inherently bad because they lose pressure in the gap between the cylinder and the barrel.

im sitting here thinking about that and i dont know... it seems wrong.

really, at the end of the day the question is what is wrong, caliber should have been what they asked.

but it does bring up a interesting question.
if you shoot the same lets say 9mm load from a semi auto and a revolver which one will have higher velocity (which should then have higher kinetic energy i would think).
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I think the question refers to the "kinetic energy" of the firearm, whether pistol (semi-auto) or a revolver, under recoil.

Considering only the type of "action", I would say that .45acp semi auto pistol would have less kinetic energy due to the slide and the recoil spring absorbing a substantial portion of the recoil impulse, compared to a .45acp revolver. However, we should factor in the weight of the handgun. A polymer framed Glock 21 (.45acp) weighs approximately half of a steel N-frame (large) S&W Model 25 in 45acp. I would say the recoil impulse would be similar, or close.

Now if we compare a steel 1911 45acp and an N-frame steel revolver, with the revolver being heavier but the 1911 has a recoil absorbing slide, I'd say somebody who has shot both please chime in. Which recoils harder?
 
easyrider604 said:
I think the question refers to the "kinetic energy" of the firearm, whether pistol (semi-auto) or a revolver, under recoil.

Considering only the type of "action", I would say that .45acp semi auto pistol would have less kinetic energy due to the slide and the recoil spring absorbing a substantial portion of the recoil impulse, compared to a .45acp revolver. However, we should factor in the weight of the handgun. A polymer framed Glock 21 (.45acp) weighs approximately half of a steel N-frame (large) S&W Model 25 in 45acp. I would say the recoil impulse would be similar, or close.

Now if we compare a steel 1911 45acp and an N-frame steel revolver, with the revolver being heavier but the 1911 has a recoil absorbing slide, I'd say somebody who has shot both please chime in. Which recoils harder?
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Felt recoil is very subjective, and many things influence it—handgun weight, handgun type, bore axis, reciprocating mass of the slide, grip angle for example.

However, in your example, the only things that contribute to total recoil momentum are the velocity and mass of the bullet and the mass of the handgun*...Newton’s law of equal and opposite reactions. Everything else is internal to the handgun and would not affect total recoil momentum.

*I suppose there’d be some effect from the propellant gases and the rotation of the bullet too.
 
carrying it to the point of kinetic energy and blunt force trauma, since the calibre was not specified (ie a 9mm bullet fired from a self loading pistol will have more kinetic energy than a .22 fired from a single action revolving cylinder pistol). However how does this affect the self loading pistol when used as a striking instrument (kinetic energy of the pistol) vrs a revolver (kinetic energy of the revolver)?
 
"so then she says, never mind, i found the answer in the readings, the semi auto has more kinetic energy."

Wondering if the answer was equally as vague as the question

or maybe she was just trying to trip up Dad, messing with his mind......
 
i actually had her show me in the reading when she found the answer.
it actually said the revolver had less.

i found the entire chapter to be very crappy.
i explained to her that barrel length and caliber and bullet weight and powder loads is what they should have been talking about.

probably a little to in-depth for a high school course i guess.
 
I have to say I completely agree with the text. All things being equal the revolver is inherently more wasteful where it needs to be most efficient. The pressures seen at the forcing cone are at a point quite high in a pistol powder burn time and even a small gap around the entire chamber will bleed off lots of pressure prior to the bullet hitting the lands and continue to bleed the pressure off until the bullet exits the muzzle.

A semi-auto will only absorb some of the pressure late in the pressure curve to run the action where most of the gases are still directed out the muzzle driving the bullet.

Take a look at my profile pic as a revolver example. That’s a lot of powder being burnt outside of the chamber! With a semi-auto you typically see very little flash out the chamber.

https://www.youtube.com/watch?v=EjQrhDKDWFk
 
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Kinetic energy of pistols? I guess it depends what their weights are and how hard you throw them.

So what are they trying to say? Recoil? Or the kinetic energy of the projectiles? That depends on caliber fully. These questions which clearly lack any understanding of firearms at all would make me question the course.
 
i stop, look at her and say.... a revolver is a pistol.

she shows me her module and it shows a 'pistol' as a semi auto pistol.
so im like.... errrr ok.


By definition a 'pistol' is a handgun with integral barrel and chamber.
 
Sinasta said:
There's revolvers and pistols and both are handguns.
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This. Pistol is not a revolver, but they're both handguns.

If you were comparing two identical loads in two identical length barrels, then I could see the book answer being the revolver is weaker due to the cylinder gap, but the question is terrible.
 
If it was a question from objective literature in an objective private school I'd say it's an obvious trick question: I'm glancing up at a 357 revolver as I type this, and it possesses no kinetic energy. Granted, I could pick it up and throw it or it could fall off the table... there is the possibility it could have some kinetic energy, but it's an inanimate piece of steel and wood. I could get a semi-auto pistol from storage, but like all my other criminally defective firearms I'm guessing it'll just lay there as every inanimate object in the world does until a sentient being moves it.

Revolvers and pistols are not really incorrect nomenclature: though it is more accurate to call them revolvers and semi-automatics as you stated.

As to the ballistics of the fired rounds in each: it depends on what any examples are so chambered for, and rounds produced. Ballistic apples to apples: a 44mag Desert Eagle semi-auto with 5", 6", 10" barrel shooting the same Winchester 240gr SP ammunition is not going to yield a substantially different muzzle velocity from a S&W 29 with same barrel lengths and test ammunition.
 
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In terms of kinetic energy, Your average semi-auto is easier to throw than you average revolver. Seeing as velocity counts more than weight, ease of throwing counts more. :)

Although, that being said, in terms of striking force, revolvers tend to be better for hammering nails, due to the lack of a dentable magazine absorbing energy.
 
At that level, subjects should be taught "broad and shallow", then divided into sections to go narrow and deep. Giving random facts without context is a bad way to teach -- students end up thinking nonsense like, "I'd rather get shot by a revolver because of the lower kinetic energy"....
 
All arguments aside, I would say that the right answer is the one that the instructor is most likely to give her marks for. The kid is going for extra credit for skool and book lerning. Let them get good grades and pass with flying colours.
Getting all of Dad's friends to help is probably going to get the kid sent to the virtual principal's office.
 
Lionel said:
All arguments aside, I would say that the right answer is the one that the instructor is most likely to give her marks for. The kid is going for extra credit for skool and book lerning. Let them get good grades and pass with flying colours.
Getting all of Dad's friends to help is probably going to get the kid sent to the virtual principal's office.
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this is how nerdy my daughter is.
she finished grade 12 a semester early.
then filled her last semester up with more courses.
now she is in college doing nursing but since she is still 18 she can still do some distance grade 12 courses so she picked up this forensics course to do WHILE she is doing her nursing.
not gonna lie, she gets all of that from her mother!
 
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