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40 S&W Big Bore ?

imperialism2024

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JMJ2 wrote:
Is 40 Cal considered a big bore caliber ?

Not unless you meant to use a "4" instead of a "0"

Seriously, though, you'll need to provide more context. Do you mean to ask if it is powerful? If it will make a bigger hole than usual? If it has a lot of recoil? Please specify.
 

JMJ2

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I mean in regards to recoil and power. My 40 cal RugerP944 has a sharp kick, when shooting 165 gr JHP and less felt recoil when shooting 180 gr FMJ. I expected more recoil from the 180 gr.
 

imperialism2024

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Recoil depends on two factors: power of the round and weight of the gun. When I shoot my Kel-Tec Sub-2000 in .40 S&W, I get more of a kick than when I shoot my AK, which fires a substantially more powerful round but weighs quite a bit more.

As far as power goes, that's also split between two factors: bullet weight and powder. My guess is that the lighter bullet has more powder behind it, producing more energy. I've also noticed that in my rifle, 165gr JHP has a sharper kick than 180gr FMJ, and that's the theory I've gone along with.

My advice, if you can accomodate it, is to get a heavier gun. You shouldn't sacrifice stopping power in the name of recoil reduction. Don't count on the second, third, or fourth shots to do what your first shot couldn't do. Granted, a 5lb .44 magnum revolver isn't for everyone (cough cough), but I wouldn't get too bent out of shape if you're dead accurate with your first shot, but can't accurately fire off your whole mag in 2 seconds.

Also, all things are relative as far as recoil go. To me, .44 magnum is average recoil, .45 is barely noticable, and a pistol-grip 12-gauge firing 3" magnum slugs is "heavy". To others, 9mm is so heavy that it's barely acceptable.
 

JMJ2

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Thanks, It depends on alot of variables I guess. I'm more accurate with the 180 gr but the 165 gr JHP seems like its more potent based on the sharp recoil. 165 gr JHP going 1050 Fps is nasty.
 

swillden

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imperialism2024 wrote:
Recoil depends on two factors: power of the round and weight of the gun
It's more complicated than that. Based on bits and pieces I've learned over the years from articles about firearm recoil and on my understanding of classical mechanics, here's my understanding of how recoil works. This is the first time I've ever tried to write it down and I thought it might be interesting to try, so here goes:

First, the energy involved is dependent only on the powder charge (obviously, where else would energy come from?). The recoil, however, is a result of many factors, and "real" recoil and "felt" recoil are different.

In an ideal gun, the real recoil energy would be exactly equal to the kinetic energy of the bullet as it leaves the muzzle. The gun would do as much work pushing back on the shooter as it does pushing the bullet forward, and no energy would be wasted (note that since the gun and bullet both start at rest, we can use the words "work" and "energy" almost interchangeably). A perfect gun like this would make no noise, so obviously we're at the "assume a perfectly spherical cow" stage, but it's a good starting point for discussing the difference between real and felt recoil.

Suppose we have such an ideal gun, and suppose it's manually-operated bolt action weapon, with no buffer springs or other energy shifting mechanisms. Given that we know the kinetic energy of the bullet as it leaves the muzzle, we know exactly how much energy will be applied to push the gun backward. To figure out how much force that energy will exert on the shooter's hands we have to know two things: How heavy the gun is and how long the "push" is.

"Energy" is a combination of three factors: mass, acceleration and distance. In fact, they're multiplied together. So, if you hold energy constant and increase mass, either acceleration or distance must decrease. In the case of a gun, increasing the mass of the bullet means that the acceleration down the barrel will be lower (and the resulting muzzle velocity will be lower, too). So, a heavier bullet will take longer to traverse a barrel of a given length.

With respect to felt recoil, that greater travel time means that the recoil energy applied to the gun will be spread out over a longer period of time, meaning the backward force on the gun will be lower. So, given two bullets with the same kinetic energy a heavier, slower bullet will result in less felt recoil than a lighter, faster bullet.

A heavier gun also reduces felt recoil. For a given amount of recoil energy spread over a given amount of time, the recoil force is constant, regardless of the mass of the ideal gun. However, force = mass x acceleration, so if you increase mass, you decrease acceleration. Less rearward acceleration means less felt recoil.

Real guns, of course, don't ideally and perfectly expend exactly half of their energy putting the bullet downrange, and pistols are particularly inefficient. What happens is that a lot of the forward-moving energy is in the form of the gases that propel the bullet down the barrel. When the bullet leaves the barrel, these gases don't stop, they also push forward out of the barrel at high speed, just like hot gases out of a rocket nozzle, and the gun does the same thing the rocket does -- it accelerates in the opposite direction of the gas flow.

This gas flow-based secondary recoil is not affected at all by the mass of the bullet, although the mass of the gun has the same effect as with the primary recoil. A long-barreled gun will transfer more of the powder charge's energy to the bullet and reduce the amount of the secondary recoil. Short-barreled firearms do the opposite. For very short-barrelled pistols (snubbies, in particular) the secondary recoil is much larger than the primary recoil, so the mass of the bullet has much less effect on felt recoil.

Real guns also often have various ways of "absorbing" recoil energy. Auto-loading weapons may use either primary recoil energy (recoil-operated) or secondary recoil energy (gas-operated or blowback-operated) to work the action, ejecting the spent cartridge and chambering a new one. Automatic pistols get a significant "softening" of felt recoil from the energy that goes to work the action, as compared to a revolver which has no such mechanisms.

Many military-style rifles also include buffer springs, which are another way to absorb this recoil energy. "Absorb" is really the wrong word, though, because the energy must go somewhere and ultimately the only place for it to go is to be converted into rearward acceleration. Essentially, some of the recoil energy gets temporarily stored in the compressed spring of the recoil buffer or the action and then is release when the spring is uncompressed. This has the effect of spreading the time over which the energy is applied to the shooter's hands, softening the felt recoil.

Finally, some guns use muzzle brakes to reduce the effect of the secondary recoil, and even to help offset recoil effects. A .50 BMG rifle with a heavily-loaded cartridge would deliver an almost unendurable recoil without its muzzle brake, but the muzzle brake uses some of the forward-moving gas expanding out of the barrel to actually apply a forward force on the muzzle brake, and hence the whole gun. Without the recoil-delaying mechanisms in a .50 BMG and the muzzle break, hot loads would have literally bonebreaking recoil.

The combination of a good muzzle brake and a heavy buffer spring can do interesting things to recoil. If you've ever fired an M-60 from a prone position, you probably noticed that you had to focus some attention on holding the butt into your shoulder because the gun wanted to "walk" forward, away from you. The M-60 has an initial rearward recoil that is only moderate and then a small forward recoil so it tends to rebound off your shoulder and walk forward.

Pulling this all together, then recoil depends on:

1. The amount of powder in the cartridge. Less powder means less recoil, all else equal. The speed at which the powder burns matters too.
2. The mass of the bullet. Heavier bullet means softer recoil, all else equal.
3. The length of the barrel. Longer barrel means softer recoil, all else equal.
4. The mass of the gun. Heavier gun means softer recoil, all else equal.
5. The design of the gun. Many guns have features that spread the recoil and make it softer.
 

deepdiver

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Within my limited understanding of ballistics, and remembering that felt recoil and actual recoil force are not the same thing and that felt recoil depends on numerous factors including the shooter's form and body build, and without getting into the physics of the thing and assuming all in the exact same firearm:

A lighter bullet at the same velocity as a heavier bullet will have less actual recoil.

A change in velocity has a greater effect than a change in bullet weight - the 8% reduction in bullet weight will have less effect than an 8% increase in velocity.

And numerous things I have read (and my personal experience matches) claim that a lighter bullet at a higher velocity will generally have a "snappier" felt recoil than a heavier bullet at a lower velocity even if both have exactly the same measured recoil.

I am guessing that the 180 gr FMJ ammo is practice ammo under 1000 fps and you already stated that the 165 g JHP has 1050 fps velocity. So you have an 8% reduction in bullet weight combined with probably about a 10% increase in velocity which will give more actual, and probably more felt, recoil.

EDIT: I started writing this and got interrupted for some time so didn't see swillden's post before I sent it. Good post swillden.
 

nova

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I consider any caliber that starts with a 4 to be "big bore"
 

deepdiver

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[font="Verdana, Arial, Helvetica, sans-serif"]Definition for "big bore" [font="Verdana, Arial, Helvetica, sans-serif"]: In the US, this term is used to describe handgun cartridges of greater power than the .38 caliber, and rifles .30 caliber and greater. In the UK, this term is used to describe rifle cartridges .40 caliber and greater.

http://www.midwayusa.com/guntecdictionary.exe/showterm?TermID=1295

Best I can find.

S0 .357, 10mm, .40, .45, .50 are "big bore"
[/font]
[/font]
 

nova

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imperialism2024 wrote:
nova wrote:
I consider any caliber that starts with a 4 to be "big bore"
Well, AFAIK, "big bore" moreso relates to big-game rifle cartridges.

And, the "4" rule excludes .357 magnum... :(
this got a big debate on another gun forum...lots of people didn't consider the .357mag "big bore" either. I don't, but I do recognize it as a powerful beast :D
 

imperialism2024

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nova wrote:
imperialism2024 wrote:
nova wrote:
I consider any caliber that starts with a 4 to be "big bore"
Well, AFAIK, "big bore" moreso relates to big-game rifle cartridges.

And, the "4" rule excludes .357 magnum... :(
this got a big debate on another gun forum...lots of people didn't consider the .357mag "big bore" either. I don't, but I do recognize it as a powerful beast :D
Then again, I guess that "big bore" technically would refer to the size of the round, not the power. A .223 is powerful, but certainly isn't "big" bore.
 

Marco

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[font="Verdana, Arial, Helvetica, sans-serif"]Definition for "big bore" [font="Verdana, Arial, Helvetica, sans-serif"]: In the US, this term is used to describe handgun cartridges of greater power than the .38 caliber, and rifles .30 caliber and greater. In the UK, this term is used to describe rifle cartridges .40 caliber and greater.

[/font]
[/font]
One man's squirt gun is another man'sCannon and vice versa.

Funny by this definition some 9mm loads (115gr.>1230fps)will be considered BIG BORE and some 45ACP, 44spl and 45LC (230gr<865fps, 200gr < 927fps, 240gr<846fps, 250gr<830fps)loads will not.

Based on gun, barrel length, ammo, if you use the ft-lbs of energy delivered.

Whilenot a Big Bore as far as bullet diameter the .357 magnum is KING in terms of defense shootings.:p


I used a 38spl+p load that delivers 383 ft-lbs from a 4in barrel as comparison.

Oh yeah, you guys forgot about the 41 magnum.

EDIT:
So no one ask for a cite this is my opinion and not a statement of fact.:D
 

Sa45auto

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To me, any caliber that starts with .4 is a big bore.



I love my .357, but I don't consider it a big bore.



Hence the age old debate between big and slow and small and fast. :)
 

deepdiver

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Agent19 wrote:
[font="Verdana, Arial, Helvetica, sans-serif"]Definition for "big bore" [font="Verdana, Arial, Helvetica, sans-serif"]: In the US, this term is used to describe handgun cartridges of greater power than the .38 caliber, and rifles .30 caliber and greater. In the UK, this term is used to describe rifle cartridges .40 caliber and greater.

[/font]
[/font]
One man's squirt gun is another man'sCannon and vice versa.

Funny by this definition some 9mm loads (115gr.>1230fps)will be considered BIG BORE and some 45ACP, 44spl and 45LC (230gr<865fps, 200gr < 927fps, 240gr<846fps, 250gr<830fps)loads will not.

Based on gun, barrel length, ammo, if you use the ft-lbs of energy delivered.

Whilenot a Big Bore as far as bullet diameter the .357 magnum is KING in terms of defense shootings.:p


I used a 38spl+p load that delivers 383 ft-lbs from a 4in barrel as comparison.

Oh yeah, you guys forgot about the 41 magnum.

EDIT:
So no one ask for a cite this is my opinion and not a statement of fact.:D
That is an interesting point and one I considered but didn't feel like looking up the KE data to check and also the reason I left out 9mm in my comment. I figured someone would call me on that and look up the KE themselves to point out my omission and save me the trouble. Not exactly how it worked out, but I appreciate that you did it all the same ;)
 

Marco

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didn't feel like looking up the KE data

Made easy.;)
Go down to the graph input the known velocity & bullet weight(below the yellow bubbles next to the words velocity/mass)then click push, pop and draw current.
The graph and yellow bubble(ME) will display energy in ft-lbs it can also do/be used for power factor.
Under lined are the words Switch to Power Factor Calculator for this data.


http://www.zknives.com/bali/bvtengy.shtml
 

molonlabetn

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JMJ2 wrote:
Is 40 Cal considered a big bore caliber ?

Thatdepends on what you are comparing it to. If you consider .17, .20 and .22 to be small-bore, and .44, .45, .50, etc... to be large-bore, I'd say that 9mm and .40 fall kinda in the middle.
 

deepdiver

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Agent19 wrote:
didn't feel like looking up the KE data

Made easy.;)
Go down to the graph input the known velocity & bullet weight(below the yellow bubbles next to the words velocity/mass)then click push, pop and draw current.
The graph and yellow bubble(ME) will display energy in ft-lbs it can also do/be used for power factor.
Under lined are the words Switch to Power Factor Calculator for this data.


http://www.zknives.com/bali/bvtengy.shtml
Very cool! Thanks for the link.
 
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