Talk:Physics of firearms

Point event
Isn't it too simplistic to discuss the accelleration of the bullet as a point event? In reality the bullet is accellerated along the entire length of the barrel. Indeed the charge in a centerfire rifle round is still combusting (and developing pressure) almost until the round leaves the barrel. This accelleration over time is very different from a point event. The impact to the target might be closer to a point event depending on the deformation and energy-shedding charistics of the round.


 * While you may be right, if we take things like this into consideration, you can also consider the air pressure inside the room in which the gun is being fired. The air pressure inside the room increases, creating a similar acceleration on a lesser level.  These effects make things overly complicated.  Let's assume, for simplicity's sake, that the gun is fired in space.


 * --LocrialTheSequel 03:34, 6 March 2006 (UTC)

The assumption that the accelleration is a point event goes grossly against the science of internal ballistics, which is a real very serious field off study. I intend to add IB stuff to this article over time. Georgewilliamherbert 02:45, 15 April 2006 (UTC)


 * This page doesn't discuss the accelleration on the bullet at all. Internal ballistics is covered on another page.
 * I think the "other information" probably also belongs in one of the ballistics pages since it isn't really talking about physics.--schroding79, 2 May 2006

Trajectory
Perhaps most importantly, this page is missing a description of the ballistic--i.e., parabolic--trajectory that bullets (and all projectiles) undergo when they are fired.
 * Ok, I missed the trajectory of a projectile page. A link would be appropriate from this page to that one, along with a short description.

Nitpick
Just to pick nits: The Mythbusters reference states they tested an M1 Garand. I seem to remember that they used the same rifle as in the episode on testing bulletproof stuff - a WWI era rifle. I think it was a Springfield. Michael Daly 20:32, 20 December 2006 (UTC)
 * From what I can tell, it's an M1. Episode 34: Bulletproof Water, 360 Swing at Annotated Mythbusters video clip from Mythbusters Episode 34 Arthurrh 00:09, 31 August 2007 (UTC)
 * I stand corrected. Thanks!  Michael Daly 23:12, 15 September 2007 (UTC)

Conservation of energy
Made some minor edits to the kinetic energy section to clarify that energy, as well as momentum, is conserved. E.g. "...allows significantly more KINETIC energy to be imparted to the bullet than to the shooter." Hope this helps. :-) Todd Johnston (talk) 05:39, 2 June 2008 (UTC)

Comment on conservation of energy
As a direct result of applying Newton's laws of motion, one can clearly see the force applied on the shooter/gun system is identical to the force applied on the bullet. Energy is directly proportional to the force (F*t, when t is time of contact - identical to both bullet and shooter).

Hence one can clearly see the energy absorbed by the shooter/gun system is equal to the energy absorbed by the bullet.

And regardless of the latter reasoning, the algebra applied in the equations on this paragraph is wrong.

I unfortunately don't have the time to correct the issue right now, but it's important to note.


 * By the way, the reason the shooter doesn't get nearly as hurt as the target (they absorb the same energy, don't they?) is because of the dramatic difference in area of impact between the two.

-- Mike

Energy is force x distance, not time. Mark Thomasmj (talk) 19:39, 8 January 2012 (UTC)

Conservation of momentum
Article says: "Assuming the gun and shooter are at rest, the force on the bullet is equal to that on the gun-shooter. This is due to Newton's third law of motion (For every action, there is an equal and opposite reaction)"

This seems incorrect, because it neglects the force of excess pressure that isn't transferred into the bullet. Attaching a compensator to the end of the barrel has no effect on bullet velocity, yet reduces the recoil of the gun by as much as 75%, by reflecting excess gasses back in the direction of the shooter. This would seem to indicate that the force of the gas is no less significant than the force of the bullet. As such, it seems that the recoil force felt by the shooter would be much greater than the force of the bullet alone.

— Preceding unsigned comment added by Yahastu (talk • contribs) 03:09, 28 July 2017 (UTC)

A gun can put less energy into the shooter than it puts into the bullet.
Seriously has anyone ever heard of a recoilless rifle? It seems like it was just forgotten about. Thedumbestone (talk) 00:34, 27 November 2020 (UTC)

Article likely in need of an expert.
Article consists almost purely of original research, writing style is amateurish, cites no sources for derivations etc. 2602:304:B1AE:E770:4952:688A:C88:E347 (talk) 05:55, 4 March 2022 (UTC)


 * There's three references, and one of them is an XCKD "What if".
 * The other two are handloading pages with only tangential relevance to the subject matter. 131.156.156.130 (talk) 02:52, 3 April 2023 (UTC)

Trains? Huh?
"This example shows the target barely moves at all. That's not to say one couldn't stop a train by firing bullets at it, it's just completely impractical."? Why is this here? There is no previous mention of trains, nor any after the statement. While it is technically true and weakly relevant, I don't think it's needed here. If anybody has an opposing opinion, let me know. Gøøse060 (talk) 13:57, 30 May 2023 (UTC)