User Panel
Posted: 6/12/2003 6:21:29 PM EDT
Specifically, concerning FMJ ammo of a given bullet design, will the one with the highest energy always penetrate the furthest?
As an example, would a 9mm with 400 lb/ft penetrate further than a 185 grain .45 with 390 lb/ft., and would they both penetrate further than a 230 grain .45 with 375 lb/ft? Thanks! |
|
Firstly FMJ is a bad choice for stopping people and 9mm FMJ is amongst the worst it has a bad reputation for over penetration.
FMJ should be used only for practice unless you have no other choice. 9mm FMJ will almost always penetrate further than .45acp FMJ. 9mm usually has a higher muzzle velocity than .45acp and a smaller cross section so it tends not to slow down as fast as .45. If you mission is to shoot through walls 9mm is a good choice if you want to stop people .45 is the winner without a doubt. Its bigger cross section allows .45 to expend more of its energy in the target. But again any FMJ is a very poor choice for stopping people. |
|
Quoted: Please God, make it stop. View Quote Who has the picture that says, "Aww jeez, not this shit again!" That's what I was thinking.... [peep].45 is best. |
|
No, No, NO! I'm not trolling. Seriously, I am not interested in stopping people. This has nothing to do with which one stops better. I want to know strictly about penetration, and specifically, if energy is directly related to penetration. This should be strictly scientific, not based on "stopping power" or some other statistics based theory.
For practical purposes, assume that we have two identicle bullets, except for their mass. The bullet with less mass is going faster than the bullet with more mass. Energy is the same. Will they both penetrate the same, or is there another variable that I've missed? |
|
Air In - Blood Out!!!
.45 Wins.... 9's are training wheels for .45's! There! I started it! |
|
They're BOTH better than the .40.
I HATE that f_ucking cartridge! |
|
HPAPIT 50BMG if you want to be sure...!
(PS---Here's some jello shots...) [url]http://www.ammolab.com/Test%20Results.htm[/url] |
|
Quoted: No, No, NO! I'm not trolling. Seriously, I am not interested in stopping people. This has nothing to do with which one stops better. I want to know strictly about penetration, and specifically, if energy is directly related to penetration. This should be strictly scientific, not based on "stopping power" or some other statistics based theory. For practical purposes, assume that we have two identicle bullets, except for their mass. The bullet with less mass is going faster than the bullet with more mass. Energy is the same. Will they both penetrate the same, or is there another variable that I've missed? View Quote Your example of two bullets that are identical except for their mass is not the same as 9mm vs .45. If you were to compare a 115gr FMJ 9mm to a 147gr FMJ 9mm, now you are talking identical except for mass (and length, obviously). Ditto for 185gr FMJ .45 ACP versus 230gr FMJ .45 ACP. In those cases, always bet on the heaviest bullet penetrating the deepest, assuming comparable chamber pressures. High sectional density (mass/area) combined with moderate velocity yields more penetration than low sectional density and high velocity. This also assumes neither bullet will yaw or fragment. It is more complicated than this but this serves as a good "rule of thumb". |
|
If they are both the same diameter the one with the most energy (by either mass or velocity) will penetrate farther. If the same weight and velocity but one is wider the narrower one will penetrate farther. IOW, if a .45 and 9mm hit a target with the same energy the 9 will penetrate farther because the .45 is fatter and thus has more drag.
|
|
Quoted: .45 and a shovel. View Quote Ain't no one gonna miss ya. Have my daughter home by midnight. |
|
Depends on how good your aim is. Shot for shot .45 is better. .45 recoil scares some people. They put more rounds on target with the 9mm.
9 mm gives you more follow up shots. Split the difference and get a .40 cal- or- Carry BOTH and you will be just fine! |
|
sherrick13, chuckhammer, thanks for reading my post long enough to have an intellegent answer to my question.
|
|
Quoted: I want to know strictly about penetration... View Quote It's time we've had a talk, son... [:D] -UHLEK- |
|
Quoted: Quoted: I want to know strictly about penetration... View Quote It's time we've had a talk, son... [:D] -UHLEK- View Quote [LOL] I missed that completely... [:D] |
|
Chuckhammer - I was thinking the exact opposite.
IF energy and diameter of the bullet were the same, and the only differences were mass and velocity, I think penetration would be the same. However, since the 9mm has a smaller diameter, and has the same energy in this instance, it should penetrate further than the larger bullet. Johnphin - Keep in mind that velocity has a much greater effect on energy than mass does (e=m x v^2). as an example: m=10 v=10 e=1000 m=20 v=10 e=2000 m=10 v=20 e=4000 |
|
Quoted: Chuckhammer - I was thinking the exact opposite. IF energy and diameter of the bullet were the same, and the only differences were mass and velocity, I think penetration would be the same. However, since the 9mm has a smaller diameter, and has the same energy in this instance, it should penetrate further than the larger bullet. Johnphin - Keep in mind that velocity has a much greater effect on energy than mass does (e=m x v^2). as an example: m=10 v=10 e=1000 m=20 v=10 e=2000 m=10 v=20 e=4000 View Quote Your point about energy (the ability to do work) is valid if the two bullets have identical drag coefficients. The problem with lighter bullets is they are shorter (for the same diameter) and therefor have higher drag. A test would tell us if the increase in drag from the lighter/shorter/faster bullet would be enough to overcome its energy advantage over the heavier/longer/slower bullet (i.ei., 185gr .45 vs. 230gr .45). You're correct that energy is more greatly effected by velocity than mass, however you stated the equation incorrectly. You forgot the 1/2: KE = 1/2 M x V^2 m=10 v=10 e=500 When calculating muzzle energy you have to be careful with units. Velocity will be in ft/s and mass will be in grains (1/7000 lb). Since you are working in the US system of units, you must convert lb force (weight) to slugs (mass). The resulting equation looks like this: ft-lb = 1/2 x gr x (1 lb / 7000 gr) x (1 slug / 32.2 lb) x (ft/s)^2 Ex: 369 ft-lb = 1/2 x 230 gr x (1 lb/7000 gr) x (1 slug/32.2 lb) x (850 ft/s)^2 |
|
it all depends on whether the shooter is weaeing marpat. I hear that adds 1000fps to any bullet fired.
A 9mm is a .45 set on stun. mike |
|
I don't know about flesh (assuming thats the medium you are reffering to) but in wet telephone books stuffed in a mailbox it is a 115 grain 9mm. Two weeks ago I tested penetration of bullets in my Taurus (9mm) PT 92 and millenium 45. 230 grain hp went through only about 1/2 phone book while 185 grain silvertip hp went almost through one book. 147 grain hp 9mm went through 2 and pressed into third while 115 grain hp went into 3 books. Hardly scientific but I dion't know the ballistic gelatin recipe and I wanted to put my mailbox to good use after some ass hit it with a bat.
|
|
Quoted: YOU HAVE TWO HANDS JUST CARRY A 9mm AND A .45!!!!!!!!!! View Quote Now for the test, which hand penetrates further, has more muzzle climb, and of course, the more accurate one? |
|
Quoted: I don't know about flesh (assuming thats the medium you are reffering to) but in wet telephone books stuffed in a mailbox it is a 115 grain 9mm. Two weeks ago I tested penetration of bullets in my Taurus (9mm) PT 92 and millenium 45. 230 grain hp went through only about 1/2 phone book while 185 grain silvertip hp went almost through one book. 147 grain hp 9mm went through 2 and pressed into third while 115 grain hp went into 3 books. Hardly scientific but I dion't know the ballistic gelatin recipe and I wanted to put my mailbox to good use after some ass hit it with a bat. View Quote You're right, this isn't close to scientific, no flame intended. A PT-92 9mm has a 5" bbl and a Millenium .45 has ~3.5" bbl. This throws the velocities way off for comparison. In addition, the 9mm 115 hp is on the lighter side of 9s where the .45 230 hp is the heaviest .45. |
|
The .458 Socom. Use the cartridge designed to take out engine blocks. That's the ticket.
|
|
The .45acp allows you the Gee I must have wrong built in factor!
Bob [:D] |
|
Do not attend a gunfight with a handgun, the caliber of which does not start with a "4".
|
|
Quoted: ...or is there another variable that I've missed? View Quote Cross sectional area and shape. A needle will penetrate farther than a manhole cover. |
|
my personal preference is the .45ACP
however, I do have a 9mm and .32ACP at the ready. (depends on location) any firearm in any caliber when you need one, is better than no firearm at all. Just be sure to effectively employ it. |
|
These tables obviously contain a lot of emperical data but interesting none the less.
Note the difference in recoil between the .40 vs the 9mm and .45acp.... [url]http://www.chuckhawks.com/handgun_recoil_table.htm[/url] [url]http://www.chuckhawks.com/handgun_power_chart.htm[/url] |
|
No one ever had to argue that the .45ACP was a good as 9mm [;)]
|
|
Quoted: it all depends on whether the shooter is weaeing marpat. I hear that adds 1000fps to any bullet fired. A 9mm is a .45 set on stun. mike View Quote Since when did guns come with a "Bitch-Slap" setting? |
|
The sound of a dead and rotting horse being senselessly beaten.... |
|
for military use, I would choose the .45 acp
cartridge, because they are only allowed to use "FMJ" ammo, the bigger 230 gr fmj slug has better stopping power than a 9mm 115 gr fmj. .45 acp 230 gr fmj has a good reputation used in combat. |
|
the standard GI .45 acp 230 gr full metal jacket round weighs twice as much as the standard GI 9mm 115 gr fmj in current use!
Getting hit by a .45 has more trauma and shock effect for a military fmj pistol rd. the shock or trauma caused by a standard .45 auto is a better man stopper than the 9mm rd. It's like getting hit by a slug. Thats why it often has a one shot stopping capability with good shot placement, the 9mm often requires multiple hits to stop a man. |
|
Quoted: the standard GI .45 acp 230 gr full metal jacket round weighs twice as much as the standard GI 9mm 115 gr fmj in current use! Getting hit by a .45 has more trauma and shock effect for a military fmj pistol rd. View Quote FYI: NATO standard (and US standard) 9mm is a 124gr FMJ projectile. |
|
Quoted: .40 View Quote Welcome to the best message board on the 'net. [:D] |
|
One of these days we just have to think of something new to fight over.
|
|
Quoted: One of these days we just have to think of something new to fight over. View Quote How 'bout AK vs AR, Republican vs Libertarian, Christian vs Atheist, Pro-Life vs Pro-Choice, Ford vs Chevy, Displacement vs Forced Induction, Revolver vs Semi-Auto, Colt vs Other ARs, 1911 vs Other Pistols, Rap vs Other Music, Kalifornia vs Other States, Porn vs Drama (?!) Never mind, you said "new". [;)] |
|
Quoted: Specifically, concerning FMJ ammo of a given bullet design, will the one with the highest energy always penetrate the furthest? As an example, would a 9mm with 400 lb/ft penetrate further than a 185 grain .45 with 390 lb/ft., and would they both penetrate further than a 230 grain .45 with 375 lb/ft? Thanks! View Quote Energy doesn't have much to do with penetration. The cross sectional density and momentum of a bullet are primarly indicators of penetration. |
|
Okay here is the senero you have to take one shot to the let arm to receive insurance payments,you get your choice 9mm or .45acp!
Enough said! Bob [:D] |
|
Sign up for the ARFCOM weekly newsletter and be entered to win a free ARFCOM membership. One new winner* is announced every week!
You will receive an email every Friday morning featuring the latest chatter from the hottest topics, breaking news surrounding legislation, as well as exclusive deals only available to ARFCOM email subscribers.
AR15.COM is the world's largest firearm community and is a gathering place for firearm enthusiasts of all types.
From hunters and military members, to competition shooters and general firearm enthusiasts, we welcome anyone who values and respects the way of the firearm.
Subscribe to our monthly Newsletter to receive firearm news, product discounts from your favorite Industry Partners, and more.
Copyright © 1996-2024 AR15.COM LLC. All Rights Reserved.
Any use of this content without express written consent is prohibited.
AR15.Com reserves the right to overwrite or replace any affiliate, commercial, or monetizable links, posted by users, with our own.