9mm vs. .45 - but different!
- Thread starter Philip Marlowe
- Start date
- Status
Philip Marlowe
Member
- Joined
- Mar 24, 2009
- Messages
- 77
HOOOOOLD ON!
I did not mean for this thread to get out of hand.
People are always looking to understand something in practical terms - I thought this would help illustrate that.
This happened to be the last "fun" piece of training we did, after two 8-hour days of training and drills (so please hold the instructor comments).
Anyway - I didn't mean for this to get out of hand. I was really just looking for comments similar to Mudriver - just fun stories of where something performed one way, and something else another.
That said, I appreciate the replies - as always!
I did not mean for this thread to get out of hand.
People are always looking to understand something in practical terms - I thought this would help illustrate that.
This happened to be the last "fun" piece of training we did, after two 8-hour days of training and drills (so please hold the instructor comments).
Anyway - I didn't mean for this to get out of hand. I was really just looking for comments similar to Mudriver - just fun stories of where something performed one way, and something else another.
That said, I appreciate the replies - as always!
burningsquirrels
Member
post matches - two teams can bring as much gun and ammo on them as they can on their belt when they get to the start line. each team has two shooters. in front are two 6x6 posts. first team to cut their post in half wins the round. round of choice? 230+ grain 45 acp. blast away at that wood! knots are the place to hit to blow big chunks out!
chieftain
Member
There is a reason Most Law enforcement agencies and the FBI use Dr Roberts results and not Hawk's.
Dr Roberts results were and are based on science, that has been reinforced with street results in feedback from the agencies themselves. Started most famously in San Diego.
Some rather famous folks used to tell us the all you need is ball ammunition too. But all us kool cats know that ain't true either.
Who and why would you trust one source over another, unless you have found someone to rationalize your personal choice. Actually I did not like Doc's choices, but science is tough to argue with. Also the modern bullets keep getting better and better. I want the best I can carry for the caliber I am carrying.
I go with the professionals, who do you use? Oh by the way, Dr Roberts started his research as a Lt Commander in the Naval Reserve where he first started working with Dr Flackler (the daddy of terminal ballistics), and also does shifts as a reserve Police officer in a city in California. He ain't just Ivory tower.
And Squirrels, If you need to stop wood posts, that is a great test. If you need to stop bad guys, read Dr Roberts.
Go figure.
Fred
Dr Roberts results were and are based on science, that has been reinforced with street results in feedback from the agencies themselves. Started most famously in San Diego.
Some rather famous folks used to tell us the all you need is ball ammunition too. But all us kool cats know that ain't true either.
Who and why would you trust one source over another, unless you have found someone to rationalize your personal choice. Actually I did not like Doc's choices, but science is tough to argue with. Also the modern bullets keep getting better and better. I want the best I can carry for the caliber I am carrying.
I go with the professionals, who do you use? Oh by the way, Dr Roberts started his research as a Lt Commander in the Naval Reserve where he first started working with Dr Flackler (the daddy of terminal ballistics), and also does shifts as a reserve Police officer in a city in California. He ain't just Ivory tower.
And Squirrels, If you need to stop wood posts, that is a great test. If you need to stop bad guys, read Dr Roberts.
Go figure.
Fred
Chieftain
Hawks doesn't have his own theories....he just collects a lot of material (and he posts the references to it) and it does that extremely well...he tends to be on the side of science and rigorous testing procedure.
People pay to access his research material. And he has first hand hunting experience all around the world.
Flacker is one of his most quoted sources.
FBI and Most LE agencies use .40 not .45.....and there are very good reasons for it...more KE than 45, more round count and better penetration against light barriers...all in a 9 mm handgun platform size....
However I agree with most of what you said in your previous post.
Hawks doesn't have his own theories....he just collects a lot of material (and he posts the references to it) and it does that extremely well...he tends to be on the side of science and rigorous testing procedure.
People pay to access his research material. And he has first hand hunting experience all around the world.
Flacker is one of his most quoted sources.
FBI and Most LE agencies use .40 not .45.....and there are very good reasons for it...more KE than 45, more round count and better penetration against light barriers...all in a 9 mm handgun platform size....
However I agree with most of what you said in your previous post.
JImbothefiveth
Member
I think what the FBi concluded was taht a round should go through at least 1 foot of ballsitics gelatin, and then the bigger the better. So, a .45 would be better than a 9mm.
Last edited:
FiremanBob
Member
- Joined
- Mar 9, 2009
- Messages
- 34
I thought this thread was going to be "different".
mljdeckard
Member
I'll remember this the next time I'm attacked by rubber blocks.
Seems like the small 9 mm is up to that task....
Look at the various tests.
http://www.brassfetcher.com/9mm Luger.html
KBintheSLC
Member
I wouldn't need to see it to believe it... its a simple matter of physics. The heavier, slower bullet hits with more momentum. This is pretty much just another 9 vs 45 thread, despite the claims made in the title. We get it, the 45 hits harder. But then again, the 500 SW mag hits harder than a 45 acp, and a 50 BMG hits even harder than that, and the 20mm Vulcan even more, and the field artillery is even better, etc... Once you go down that road, it never ends.
I won't be rushing out to sell my 9's quite yet. They still have a valid place in my safe, my pocket, and my hip holster.
...
This expression is exactly what makes my head going :banghead::banghead::banghead:
It is frankly a non-sensical statement..
The narrower 9 mm plows through easily while the 45 meets more resistance so the block moves....momentum has absolutely NOTHING to do with it....hit the block with a FMJ .223 (4 times the 9 mm or the 45 energy) and it probably will move even less than with the 9 mm...
BlindJustice
Member
Seems this thread is going outside of
handgun cartridge of light and fast versus
heavy and slower real quickly....
I'd like to pop those rubber blocks with
A 115 gr. FMJ versus 147 gr. FP federal
and see which moved the block more.
I know with water filled pumpkins and the same
bullet - Gold Dots, the .45 ACP 200 gr. beats the 9MM x 19
124 gr. - both Double Tap. all to heck for the exit
and hole splash factor
Randall
handgun cartridge of light and fast versus
heavy and slower real quickly....
I'd like to pop those rubber blocks with
A 115 gr. FMJ versus 147 gr. FP federal
and see which moved the block more.
I know with water filled pumpkins and the same
bullet - Gold Dots, the .45 ACP 200 gr. beats the 9MM x 19
124 gr. - both Double Tap. all to heck for the exit
and hole splash factor
Randall
pneumagger
Member
- Joined
- Apr 22, 2009
- Messages
- 10
Momentum has ALOT to do with it. Assuming the bullet does not travel completely through the block, it is an inelastic collision.
The distance the block moves is a function of the net imparted velocity... which means a momentum balance equation.
M1V1 + M2V2 = MV
You can see that a .45 will transfer MUCH more momentum.
A sliding frictional force Ff (rougly equal for each block) is imparted over some distance (D) until the work done by friction overcomes the imparted energy.
Then the block stops moving. You added the energy and the friction takes it away.
W = Ff*D = dE (dissipated energy)
E=1/2*MV^2 (imparted energy) <--- but this velocity is the result V of the momentum balance
This is where ENERGY comes into the ballistic mix - after momentum does it's thing.
So this energy is actually the energy transferred via momentum... not the muzzle energy of the shot.
Energy is the capacity to do work... but in this case energy is doing the work via momentum transfer.
The simple fact is: Until velocities/energies where fluid dynamics begin implementing significant hydrostatic shock and fragmenting/exploding bullets... momentum transfer is king. This means pick the largest caliber you can shoot effectively with.
(I actually a carry a 9mm, for what it's worth)
ScareyH22A
Member
- Joined
- Feb 25, 2009
- Messages
- 468
.45 had more surface area making contact with the rubber right? Imagine jabbing that rubber block with a fencing word real hard. Then imagine gently hitting it with a hammer.
Fast and sharp is not gonna move things as well as slow and blunt. Energy carried only matter to some extent.
But in the end, I'm sure if you stabbed someone with the sword, they'd need to call 911 vs you gently hitting them with a hammer.
But a .45 is a fast hammer.
Fast and sharp is not gonna move things as well as slow and blunt. Energy carried only matter to some extent.
But in the end, I'm sure if you stabbed someone with the sword, they'd need to call 911 vs you gently hitting them with a hammer.
But a .45 is a fast hammer.
coltoriginal
member
- Joined
- Apr 23, 2009
- Messages
- 14
This has gone too far in a nonsensical direction and I feel I must step in.
Didn't any of you pass high school physics?
Inertia (Momentum) is calculated by the equation P=mv (mass*velocity)
going by bullet numbers imparted earlier this thread that means
9mm 147gr @ 1032 fps = 147x1032 = 151704 gr∙fps
9mm 124gr @ 1181 fps = 124x1181 = 146444 gr∙fps
45acp 230gr @ 875 fps = 230x875 = 201250 gr∙fps
(standardized metric is kg∙m/s but i'm too lazy to do the conversions and units are arbitrary anyway in a direct comparison)
Knowing Newton's 2nd Law, if the bullet stops in or at the block the force acting on the block is equal to the inertia of the bullet.
Jjust to crunch a few more numbers for you, this shows 230 gr 45acp has roughly 32.66% more momentum than the 147 gr 9mm @ whatever range these were chrono'd at. OP does this represent your findings? i.e. block moving roughly 30% more per shot for 45 vs 9mm. (keep in mind there are many other variables such as overcoming the static friction of the block, angle of impact etc..., so this is a very crude calculation)
This is not an attempt to propagate the 45 this is just the mathematical representation of what the OP saw.
As for the real world caliber effectiveness argument, that horse died a long time ago, is rotting, and smells terrible. Neither of these calibers is "not-enough", and either will kill the sh*t out of almost any living thing given a decent shooter does their part. (and disregarding hunting ethics of course)
I would say neither is outright "better" but they have noteworthy differences. For long range accuracy/trajectory/penetration 9mm all the way. For short range rubber-block moving, and punching slightly larger holes in squishy things .45 is better (noteworthy: in medium to long range penetration trials the 9mm significantly outclasses the 45. see government tests using steel army helmets.)
Last but not least this is directed toward saturno_v:
energy is slightly more complicated so it makes sense they do that for you
I hate to disappoint you but ArmedBear is right. In accounting for hydrostatic shock and Weatherby velocities it does matter (in fact it is all that matters). handguns will never get there. fire all the +p++ super 9mm you can find but until you get to high power rifle velocities some 3x the speed of a 9mm all you've done is increase your penetration.. which 9mm's have plenty of already
Didn't any of you pass high school physics?
Inertia (Momentum) is calculated by the equation P=mv (mass*velocity)
going by bullet numbers imparted earlier this thread that means
9mm 147gr @ 1032 fps = 147x1032 = 151704 gr∙fps
9mm 124gr @ 1181 fps = 124x1181 = 146444 gr∙fps
45acp 230gr @ 875 fps = 230x875 = 201250 gr∙fps
(standardized metric is kg∙m/s but i'm too lazy to do the conversions and units are arbitrary anyway in a direct comparison)
Knowing Newton's 2nd Law, if the bullet stops in or at the block the force acting on the block is equal to the inertia of the bullet.
Jjust to crunch a few more numbers for you, this shows 230 gr 45acp has roughly 32.66% more momentum than the 147 gr 9mm @ whatever range these were chrono'd at. OP does this represent your findings? i.e. block moving roughly 30% more per shot for 45 vs 9mm. (keep in mind there are many other variables such as overcoming the static friction of the block, angle of impact etc..., so this is a very crude calculation)
This is not an attempt to propagate the 45 this is just the mathematical representation of what the OP saw.
As for the real world caliber effectiveness argument, that horse died a long time ago, is rotting, and smells terrible. Neither of these calibers is "not-enough", and either will kill the sh*t out of almost any living thing given a decent shooter does their part. (and disregarding hunting ethics of course)
I would say neither is outright "better" but they have noteworthy differences. For long range accuracy/trajectory/penetration 9mm all the way. For short range rubber-block moving, and punching slightly larger holes in squishy things .45 is better (noteworthy: in medium to long range penetration trials the 9mm significantly outclasses the 45. see government tests using steel army helmets.)
Last but not least this is directed toward saturno_v:
You might think its a nonsensical statement but numbers can't lie. If the op said the 9mm's were passing clean through you might be on to something, however he did not state that and i really doubt that is what happened if their block was moving at all.
get real.. the variable difference of wind resistance between a 45 and 9mm during the course of its flight and in regards to this experiment are completely negligible.
Perhaps Momentum is not mentioned because even a stoned monkey can calculate it on his own, given the information they provide.
energy is slightly more complicated so it makes sense they do that for you
I hate to disappoint you but ArmedBear is right. In accounting for hydrostatic shock and Weatherby velocities it does matter (in fact it is all that matters). handguns will never get there. fire all the +p++ super 9mm you can find but until you get to high power rifle velocities some 3x the speed of a 9mm all you've done is increase your penetration.. which 9mm's have plenty of already
Last edited:
Tropical Buzz
Member
Size matters sometimes, but...
The difference in diameter between .45 and 9mm bullets is less than 1/10 of an inch. Look at a ruler to put it in perspective. The difference in frontal area ("size") is .072 sq.in. Again - less than 1/10 of a square inch! Factor in the elasticity of skin and living tissue and it becomes even more insignificant. Ignoring the variables of bullet expansion and focusing strictly on the size myth, if they both penetrate to 12" for example, the difference in size (volume) of the wound channels will be only 0.86 cubic inches or less than 1 cubic inch!!. The often bantered marble / bowling ball analogy is way beyond exaggeration. It would be more accurate to ask "would you rather get hit by a marble or by a slightly bigger marble?"
My point is that within a reasonable range of handgun cartridges, the "size" of the bullet is far, far less of a factor than many like to believe.
The difference in diameter between .45 and 9mm bullets is less than 1/10 of an inch. Look at a ruler to put it in perspective. The difference in frontal area ("size") is .072 sq.in. Again - less than 1/10 of a square inch! Factor in the elasticity of skin and living tissue and it becomes even more insignificant. Ignoring the variables of bullet expansion and focusing strictly on the size myth, if they both penetrate to 12" for example, the difference in size (volume) of the wound channels will be only 0.86 cubic inches or less than 1 cubic inch!!. The often bantered marble / bowling ball analogy is way beyond exaggeration. It would be more accurate to ask "would you rather get hit by a marble or by a slightly bigger marble?"
My point is that within a reasonable range of handgun cartridges, the "size" of the bullet is far, far less of a factor than many like to believe.
this can be debated forever ,i really think the 9mm is a very good round, yes very good, i would'nt carry it in my Keltec pf9, and oh yeah, it fit's in my pocket for very good for concealment, and im confident that with the right placement of shot's from the golddot's that i load her, it could take anybody down, ....that being said, in between my bed mattress lies my 1911 with 230gr gold dots as well, i just have more confidence in my bigger club,i just think bigger is better, not that the smaller of the 2 is not lethal.
bigfatdave
Member
No, the heavy, slow rock hits with more surface impact, and thus has more stopping power!
TropicalBuzz wins, thread over, everyone can go to the range and practice now.
Coltoriginal
Yes the formula to calculate momentum is extremely simple.
What momentum enthusiast keep failing to recognize is the little statement "all else being equal".....
The real world doesn't happen in a vacuum...
You say:
I agree completely....infact we do not use bullets to move rubber blocks.....the 45 moved the blocks more because it meets more resistance to penetration due to his larger cross section so it impart more movement to the block...I do not think it's very hard to understand....tap that rubber block with a given hammer and measure its movement...then whack him harder with the same hammer...the hitting mass did not change...you increased both momentum and, even more the KE.
Momentum matters more when you hit a given target with the same cross sectional area, same energy but one bullet is longer (and heavier assuming the same material and construction)...that is when we calculate SD.
Momentum, as independent, abstract, alone, variable, doesn't matter much in the real world of firearms....in some specific circumstances it does matter more...
Yes the beloved standard 45 round has more momentum than a 9 mm standard round, I give you that.....does that means that a 45 is more effective than a 9 just because of momentum....definitely not
Indeed the OP did not mention the difference in penetration between the two calibers...it would be interesting to know that...
Not true....aerodynamic friction is a substantial element during bullet flight (cross section and shape)...
Hydrostatic shock has never been proven....you can read some literature by Dr. Martin Fackler, FBI studies and others....
Pneumagger
If the bullet doesn't travel completely through the block it doesn't means it's an inelastic collision....would you care to elaborate more your reasoning??
In the real world of firearms, after the introduction of smokeless powder we moved from large heavy bullets towards more aerodynamic, lighter, faster ones for very good reasons....speed kills indeed...
To come full circle again: Why a 357 Mag it's a better stopper than a 45 ACP despite the heavier fortyfive slug???....why a 357 is considered more adequate, let's say, against a black bear than the glorious fortyfive?? ...You guessed right...because of its higher energy and better SD
Case closed, I hope...
Yes the formula to calculate momentum is extremely simple.
What momentum enthusiast keep failing to recognize is the little statement "all else being equal".....
The real world doesn't happen in a vacuum...
You say:
I agree completely....infact we do not use bullets to move rubber blocks.....the 45 moved the blocks more because it meets more resistance to penetration due to his larger cross section so it impart more movement to the block...I do not think it's very hard to understand....tap that rubber block with a given hammer and measure its movement...then whack him harder with the same hammer...the hitting mass did not change...you increased both momentum and, even more the KE.
Momentum matters more when you hit a given target with the same cross sectional area, same energy but one bullet is longer (and heavier assuming the same material and construction)...that is when we calculate SD.
Momentum, as independent, abstract, alone, variable, doesn't matter much in the real world of firearms....in some specific circumstances it does matter more...
Yes the beloved standard 45 round has more momentum than a 9 mm standard round, I give you that.....does that means that a 45 is more effective than a 9 just because of momentum....definitely not
Indeed the OP did not mention the difference in penetration between the two calibers...it would be interesting to know that...
Not true....aerodynamic friction is a substantial element during bullet flight (cross section and shape)...
Hydrostatic shock has never been proven....you can read some literature by Dr. Martin Fackler, FBI studies and others....
Pneumagger
If the bullet doesn't travel completely through the block it doesn't means it's an inelastic collision....would you care to elaborate more your reasoning??
In the real world of firearms, after the introduction of smokeless powder we moved from large heavy bullets towards more aerodynamic, lighter, faster ones for very good reasons....speed kills indeed...
To come full circle again: Why a 357 Mag it's a better stopper than a 45 ACP despite the heavier fortyfive slug???....why a 357 is considered more adequate, let's say, against a black bear than the glorious fortyfive?? ...You guessed right...because of its higher energy and better SD
Case closed, I hope...
wow, some of you guy's should really consider seeking employment with ballistic's lab.
The .45acp is a direct descendant of the .45lc which was considered the magnum of the day and more or less duplicates it ballistically with similar bullet weights. This isn't scientific, but we can all agree that any six-shooter of the day in that caliber was highly regarded and effective.
This doesn't make the .45acp the better round, but sometimes being "technically better" can be subjective.
I have 9mm, .38spl, .40s&w and the .45acp and they all fill their special niches.
If I were to keep one it'd probably be the G23 in .40s&w as it retains nice median qualities of both the 9mm in capacity and gun size and the .45acp in power.
This doesn't make the .45acp the better round, but sometimes being "technically better" can be subjective.
I have 9mm, .38spl, .40s&w and the .45acp and they all fill their special niches.
If I were to keep one it'd probably be the G23 in .40s&w as it retains nice median qualities of both the 9mm in capacity and gun size and the .45acp in power.
Energy vs momentum
True, but not all of the energy is going to do work. Some of it gets wasted. So which delivery system achieves a higher work-to-energy ratio (i.e. efficiency)?
My humble observation/opinion:
A smaller, faster bullet with equal kinetic energy will expend a greater proportion of its energy towards the creation of cavitation and heat. At handgun level velocities, these are of questionable value. A hot .357 magnum load might deliver some "shock" value, but I doubt a 9mm does. And while a 20-pound depleted uranium shell launched at 2000 fps might cause trees to burst into flames, I doubt a 9mm bullet will do any kind of heat damage to human tissue. In this specific setting, a 230 grain .45 caliber bullet should theoretically be capable of doing more work (defined as tissue destruction) when compared to a 115 grain 9mm bullet, given an equal kinetic energy.
Does this mean that slower, heavier bullets are always better? No. This is just pertaining to specifically shooting people within a certain range of velocities. History seems to show that .357 magnum and .45 ACP are both fairly similar in effectiveness for SD. But consider the average kinetic energy difference. The .357 takes a much higher kinetic energy to achieve this.
True, but not all of the energy is going to do work. Some of it gets wasted. So which delivery system achieves a higher work-to-energy ratio (i.e. efficiency)?
My humble observation/opinion:
A smaller, faster bullet with equal kinetic energy will expend a greater proportion of its energy towards the creation of cavitation and heat. At handgun level velocities, these are of questionable value. A hot .357 magnum load might deliver some "shock" value, but I doubt a 9mm does. And while a 20-pound depleted uranium shell launched at 2000 fps might cause trees to burst into flames, I doubt a 9mm bullet will do any kind of heat damage to human tissue. In this specific setting, a 230 grain .45 caliber bullet should theoretically be capable of doing more work (defined as tissue destruction) when compared to a 115 grain 9mm bullet, given an equal kinetic energy.
Does this mean that slower, heavier bullets are always better? No. This is just pertaining to specifically shooting people within a certain range of velocities. History seems to show that .357 magnum and .45 ACP are both fairly similar in effectiveness for SD. But consider the average kinetic energy difference. The .357 takes a much higher kinetic energy to achieve this.
Last edited:
The two cartridges are not exactly comparable....the 45 LC original blackpowder load was throwing a 255 g.r bullet (higher SD compared to a 45 ACP) to circa 1000 fps, developing 580-600 ft/lb of KE.
Almost double the amount of your typical 230 gr. 45 ACP....
The 45 LC is more comparable to a 357 Magnum in term of performances...
Gloob
With the same impact energy a bullet with smaller frontal area all else being equal (SD, shape, construction, etc...) will penetrate better....a larger bullet will create a larger wound channel...they will expend their energy in a slightly different way.
The smaller bullet will actually be more "efficient" because of the "easier" penetration...but as we know, overpenetration can be a disadvantage (dangerous and wasted energy outside of the intended target).
So it all depends...if you want the largest wound channel the larger bullet will serve you better...if you want maximum penetration the smaller bullet will do it....
With the same impact energy a bullet with smaller frontal area all else being equal (SD, shape, construction, etc...) will penetrate better....a larger bullet will create a larger wound channel...they will expend their energy in a slightly different way.
The smaller bullet will actually be more "efficient" because of the "easier" penetration...but as we know, overpenetration can be a disadvantage (dangerous and wasted energy outside of the intended target).
So it all depends...if you want the largest wound channel the larger bullet will serve you better...if you want maximum penetration the smaller bullet will do it....
- Status