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Agent19
Regular Member
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Posted: Fri Jan 25th, 2008 03:55 pm |
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Ok then if I shoot someone twice with a 22 that would be the equivalent of a 44.
but the dia of .44spl/.44mag is .429 
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Liko81
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Posted: Fri Jan 25th, 2008 05:21 pm |
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Agent19 wrote: Ok then if I shoot someone twice with a 22 that would be the equivalent of a 44.
but the dia of .44spl/.44mag is .429
And on top of that, area of a circle is found by A=(pi)r2. Double the radius and you get roughly four times the cavity size.
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Heartless_Conservative
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Posted: Fri Jan 25th, 2008 08:14 pm |
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I had a guy tell me once that a .45 ACP had some almost mystical power, so that if you shot someone with one with one, it knocked them down, no mater where you hit them.
To illustrate his point he told a story of a guy who was being threatened by this giant of a man. The victim shot at this giant with his .45 and the big guy went down.
the went over to the downed assailant and found him unconscious. the only mark on him was where the .45 had nicked his finger.
He had a straight face when he told me this and he really believed it. 
Tarzan
Well I suppose it's possible that the guy fainted when he relized he was getting shot at, but I would think that such a possibility would be a bit hard to generalize.
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Legba
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Posted: Fri Jan 25th, 2008 08:48 pm |
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molonlabetn wrote:
*NOTE: ft-lb is actually not the correct units for energy... it should read ft^2-lb/s^2 so actually... it wouldn't be to far fetched for a box of ammo to list the performance as 'calories per serving'.
The ft-lb is a correct unit of energy. A pound is a unit of force, not mass (it's a slug-foot per second squared, in the non-metric physics world, the "slug" being the relatively obscure unit of mass in the imperial/avoirdupois/pre-metric system). A force acting over a distance gives units of energy, the foot-pound, in this case.
-ljp
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Weak 9mm
Regular Member
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Posted: Fri Jan 25th, 2008 09:50 pm |
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In physics and engineering I recall having to make the distinction between pound force (lbf) and pound mass (lbm). I do recall now that I've been looking things back up in my books that as long as you're consistent, you could choose either one. Depending upon what you want to do, one will be an easier choice than the other and will reduce the amount of calculation that needs to be done.
If you say that what you "weigh" when you get on the scale is your pound "force" (lbf), then you simply have to make sure that when you do something like F = m*a using lbf, you remove the effect that gravity has on your "weight" to make it a mass. So you must write it as F = m*a/gc, where gc is apparently ~37.2 lb*ft/(lbf*s^2) (this is obviously only if you make m a lbf).
If you say that what you "weigh" when you get on the scale is you pound "mass" (lbm), then you do not need to take into account the effect of gravity on your "weight" (Because you're saying it's a mass) when doing the calculation F = m*a. But when describing the lbf on Earth, you would need to multiply the "weight" (Once again, a mass) times the acceleration due to Earth's gravity to get the lbf on Earth.
I recall the former method being better for when I was doing statics problems in a MAE course, because you can simply assume the weight is the actual force and not do any additional steps. It makes sense that you'd want to use the latter in physics, where acceleration is highly variable depending upon where you are in space. We often had to write programs modeling the interaction of two or more moving objects in space, where the gravitational effect they had was constantly changing. The gc used on Earth would have no purpose there, only serving to add extra steps to the calculations the program was repeating every dt to find the "updated" gravitational force after every time interval (The objects were of course, changing position relative to one another over time).
Last edited on Fri Jan 25th, 2008 09:56 pm by Weak 9mm
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SouthernBoy
Regular Member
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Posted: Fri Jan 25th, 2008 10:59 pm |
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Agent19 wrote: Ok then if I shoot someone twice with a 22 that would be the equivalent of a 44.
but the dia of .44spl/.44mag is .429
You're close. The diameter of a .44 Magnum bullet is .430". The distance between the lands in the barrel is .429". Just like a .357 Magnum bullet, and a .38 Special, is .358" in diameter.
Last edited on Fri Jan 25th, 2008 10:59 pm by SouthernBoy
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roscoe13
Regular Member
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Posted: Sat Mar 8th, 2008 05:52 am |
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I would have started in on the conversation with "You, sir, are full of s***", and gone on from there...
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imperialism2024
Regular Member
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Posted: Sat Mar 8th, 2008 11:52 pm |
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In my mind, 9mm, .45, .40... for all intents and purposes, they're the same, except for ammo cost. Put a "magnum" after the caliber, and then we have a discussion on our hands.
Hilarious explanation in the OP, though...
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Hef
Regular Member
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Posted: Sun Mar 9th, 2008 05:41 pm |
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It's all about the grain-feet per second (gfps). The mass of the projectile times it's muzzle velocity (which varies based on barrel length) is the measure of energy by which to compare the projectiles. Using this measure, the particular type and caliber of ammunition - as well as the weapon it is fired from - factors into the equation when comparing energy delivered.
Example:
Ammunition type "A" (JHP) in .45ACP is a 230grain projectile, with a muzzle velocity of 850fps when fired from a 5" 1911 pistol.
230gr X 850fps = 195,500gfps
Ammunition type "B" (JHP) in 9mm Parabellum is a 113grain projectile, with a muzzle velocity of 1310fps when fired from 4" Springfield XD.
113gr X 1310fps = 148,030gfps
148,030/195,500 = 32% greater energy from the .45ACP
If the .45ACP ammo compared were FMJ, which is less efficient in delivering all of it's energy than JHP, while the 9mm remained JHP, the gap would close between the 2 rounds.
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professionaladventurer
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Posted: Sun Nov 15th, 2009 05:58 pm |
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I am pretty sick of the so called experts and so I did some math, research and posted: http://www.professionaladventurer.com/2009/11/best-combat-hand-gun.html
The are all tool's you need the one that's right for your needs and works in a way you like.
Attached Image (viewed 219 times):
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Interceptor_Knight
Regular Member
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Posted: Sun Nov 15th, 2009 11:49 pm |
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An intruder entered a garage below the apartment of 65 year-old Lawrence Hanson III on St. Clair Avenue in Cleveland, at approximately 2:45 a.m. Hanson spotted the intruder breaking through the steel doorway, put on his boots, and grabbed his 9mm pistol. Hanson chased the man out of his garage and to a fence about 40 feet away. He repeatedly warned the intruder to stop, informing him that he had a gun. The intruder turned to walk towards him. Fearing for his life, Hanson shot the man once in the chest. The intruder dropped to the ground and died soon after.
Plenty of other stories where this one comes from.....
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Interceptor_Knight
Regular Member
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Posted: Sun Nov 15th, 2009 11:55 pm |
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professionaladventurer wrote: I am pretty sick of the so called experts and so I did some math, research and posted: http://www.professionaladventurer.com/2009/11/best-combat-hand-gun.html
SS196 is pretty much what is available to civilians and will not only penetrate a class III vest (not considered “armor piercing” by the ATFE as this round will not penetrate a SAPI or trauma plate) and then expand and come apart on the other side.
According to FNH tests, SS196 will not defeat a Class III vest. Do you have a link to a test which shows otherwise?
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PT111
Regular Member
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Posted: Sun Nov 15th, 2009 11:59 pm |
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All this talk about 9mm and .45 but from the recent news reports if you want to kill a cop you have to use a 5.7mm bullet, the most deadly ammo of all. So there is your answer.
For the uninformed 5.7 millimeters = 0.224409449 inches 
Last edited on Mon Nov 16th, 2009 12:01 am by PT111
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Mike_Hawke
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Posted: Mon Nov 16th, 2009 12:07 am |
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Liko81 wrote: Both the 45ACP and the 9mm are subsonic from most pistols, even overloaded. +P+ in 9mm MIGHT be supersonic from a full-size 4.5"-barreled handgun, but for practical purposes a defense handgun is subsonic.
Are you kidding me? The speed of sound is ~1,100 ft/sec. Standard pressure 115gr 9mm easily passes that mark.
As for the OP, firearms "experts" at gun shops are like the car "experts" at NAPA - generally idiots.
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professionaladventurer
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Posted: Mon Nov 16th, 2009 06:24 pm |
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I sure do, I did the test (or rather a bunch or tests) SS196 and 44 layers of Kevlar.
http://www.youtube.com/watch?v=1KVcWqxi0EQ
Last edited on Mon Nov 16th, 2009 06:28 pm by professionaladventurer
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professionaladventurer
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Posted: Mon Nov 16th, 2009 06:27 pm |
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If you don't know most of the BANG/CRACK from your weapon is from the GAS coming out of the barrel not the bullet.
- http://www.professionaladventurer.com
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Mike_Hawke
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Posted: Mon Nov 16th, 2009 09:40 pm |
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professionaladventurer wrote: I sure do, I did the test (or rather a bunch or tests) SS196 and 44 layers of Kevlar.
http://www.youtube.com/watch?v=1KVcWqxi0EQ
Wow, very interesting video. I'm surprised the .22 went through. I suppose it has more to do with velocity and surface area of the bullet tip than anything.
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Nutczak
Regular Member
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Posted: Tue Nov 17th, 2009 04:33 pm |
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Ok, so you got the handgun caliber ballistics laid out, I think it is time to straighten out the confusion behind peoples belief that shot cannot be fired through a rifled barrel thinking it will damage the gun, and slugs through tight chokes.
A rifled barrel will not be damaged by shooting shot through it! The shot remains in the plastic cup until it exits. Even if it didn't stay in the shot-cup, it will not damage a rifled barrel. Shot is lead, barrels are steel. you are not going to deform steel with lead no matter how hard you try
The reason you do not want to shoot shot through a rifled barrel is because the rifling spins the shot cup, which causes funky patterns downrange and very bad accuracy and patterning.
Chokes & slugs!!
Slugs can be shot from any size choke on a shotgun, the slug has ridges on its edge that resemble rifling, these are there so the slug can compress properly if fired through a tight choke. Many people feel the rifling ridges that are cast into slugs is only there to impose a stabilising spin to the projectile, well it has another purpose too, and that is so it can fit through a tight choke.
And for you smoothbore shotgun people that waste your money to shoot Sabot-slugs, those are made for rifled barrels, if you do not have a rifled slug barrel for your shotgun, do not use them! Stick with the regular slugs you'll get better ballistics. A sabot-slug fired through a smooth barrel will tumble downrange and usually keyhole the target.
So avoid shot through a rifled barrel because of the crappy ballistics, not because you think it is going to damage the barrel.
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Mike_Hawke
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Posted: Tue Nov 17th, 2009 05:23 pm |
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Nutczak wrote: Slugs can be shot from any size choke on a shotgun, the slug has ridges on its edge that resemble rifling, these are there so the slug can compress properly if fired through a tight choke. Many people feel the rifling ridges that are cast into slugs is only there to impose a stabilising spin to the projectile, well it has another purpose too, and that is so it can fit through a tight choke.
Careful with that one. There are many slugs (some Brenneke models comes to mind) that are jacketed and WILL NOT squeeze through at any choke or through tight chokes. Not all slugs are designed to allow firing through a choke, especially a tight one. Always be sure to check with the manufacturer before deciding to blow the gun up in your face.
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thx997303
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Posted: Tue Nov 17th, 2009 05:56 pm |
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Really now? And what may I ask, are these slugs made out of?
If these jacketed slugs are made the same way a normal jacketed round is made, then they indeed will squeeze through a choke.
It's called being swaged down. The lead is displaced and makes the round longer.
And the jacket would normally be made of copper or brass, which will definitely swage down.
Now, whether they would swage down at safe pressures and fire fine or not, I cannot say. I've never tried it.
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