.380 or .38 spl

[livnhel]

Is the .380 95 gr. round even close to a .38 spl 125 gr.? Both FMJ .
.380 in Sig 232 8 shot.
.38 spl in 2" snub 5 shot. Thanks

[Ricochet]

Close with respect to what?? Muzzle energy?? The .38 special is usually a more powerful round than the .380 acp. I don't have any numbers at my fingertips. I'll check back with some later if the other guys don't beat me to it.

I assume you were not merely talking price. ;D

[Ricochet]

OK, I'm back. Here is some info from the PMC Ammo site: www.pmcammo.com/handballistics.php

.38 special FMJ 132 grain -- Muzzle energy = 207 ft.lbs at 840 fps.
.380 auto FMJ 90 grain -- Muzzle energy = 169 ft. lbs. at 920 fps.

Other ammo may advertise different results. This indicates to me that the .38 special (above) has about 22% more punch than the .380 based on the energy. The .38 special projectile is 46% heavier but is traveling a little slower.

Take it for what it's worth. ;D

[Callahan]

.38 special FMJ 132 grain -- Muzzle energy = 207 ft.lbs at 840 fps.
.380 auto FMJ 90 grain -- Muzzle energy = 169 ft. lbs. at 920 fps.


But, if you shop a bit more for .380 you find:
Cor-Bon will give you 1050FPS

RBCD will get you 1500/283!

Both of those more powerful than .38 Special.

[klmhq]

You know, that's one thing that always confused me. The energy of a bullet.

Kinetic Energy is equal to mass times velocity squared (K_e=mv²). So a faster bullet of the same weight should have more energy... obvious right.

But if the bullets are different masses, then a lot of mass only increases the Kinetic Energy a little, but a little extra velocity increases the Kinetic Energy a lot.

Based on this (and not having the conversion factors handy) --
.38 special FMJ 132 grain -- Muzzle energy = 207 ft.lbs at 840 fps.
.380 auto FMJ 90 grain -- Muzzle energy = 169 ft. lbs. at 920 fps.

The .38 Special has a Kinetic Energy of 132 x 840² or 93,139,200 grain x fps²

The .380 has a Kinetic Energy of 90 x 920² or 76,176,000 grain x fps²

Hmmm... OK, not what I was expecting. I guess the numbers are closer than I thought. Assuming the Cor-bon has a 90 grain bullet, it will havea Ke of 99,000,000 and change grain x fps²

Wow, that's really not what I expected. I understand that a bigger, heavier bullet will make a bigger hole and probably transfer energy more effeciently into the target, but the lighter, faster bullet sounds as though it shold have lots more total Ke.

Interesting.

Just goes to show you. Never assume, do the math.

[Callahan]

KLMHQ:

Run the numbers on 40 and 45, say the 230 grain classic .45 round vs. a 165 or 189 grain in .40.

Ought to be interesting.

[Ricochet]

Also, if you are talking stopping power or knockdown potential, then it is not merely the kinetic energy at impact but how much of that energy is transferred to the target body. That's where calculations start breaking down and test data or experience pick up.

Consequently, FMJ's don't expand and thus transfer less energy. JHP's expand and transfer more energy. And this naturally leads to the "bigger is better" mentality. But like has been said before, a well placed .38 is better than a .45 that misses.

;D ;D

[Callahan]

Yep, the Cor-Bon is 90-grain, 1050/220

[klmhq]

Ricochet: That's very true. The transfer of that Kinetic Energy into a target can be figured a couple of ways. The easiest would be to measure how far the bullet travelled into a target. Using that you could figure a rough deceleration value and figure out the energy transfer effeciency. If the bullet went all the way through, you could use it's entrance velocity and exit velocity to figure the same thing. Of course, it would be a VERY rough value...

Callahan: OK using the numbers from the Ammo Ballistics site here you go... I also include the .357 Sig since I was a curious monkey.

Velocity is at 25 yards and in feet per second

.45 Auto - 230 grain FMJ - 809 fps So it's Kinetic Energy is 230 x 809² or 150,530,630 grains x fps²

.40 S&W - 165 grain FMJ - 955 fps. So it's Ek is 165 x 955² or 150,484,125 grains x fps²

.357 Sig - 124 grain FMJ/FP - 1263 fps. It's Ek is 124 x 1263² or 197,800,956 grains x fps²

Neat. Effectively the .45 and .40 have the same Kinetic Energy at 25 yards, while the .357 Sig has almost 33% more. Of course, all three are waaaaay more than a .380.

Guns, I'm still an amatuer. Physics, I understand.

[Ricochet]

Yep, Pistolero. I like your thinkin'. From a physics standpoint, if there is no penetration, then all the Kinetic energy has been transferred to the target over some small distance & very small increment of time. To me that is knockdown power. I don't want penetration in a self defense round. I want maximum energy transfered to the target (along with critical damage to internal organs). You can knock a guy down with a bowling ball but he'll get back up. You can knock him down with a .45 acp and he likely won't. Hehe!

Livnhel is probably wishing he hadn't opened this bucket of worms, but I'm having fun. ;D

I am also becoming more intrigued by the 0.357 Sig cartridge. I have a new Springfield XD-40 and I hear I can get a drop in .357 Sig barrel for it -- probably from Barstow. That sounds like something I may consider in the future.

[Callahan]

Livnhel, I guess you have seen that with the right .380 loading you can equal or slightly exceed a traditional .38 Special load.
Then, when you go into .38 Special +P loads, I suspect you will leave the .380 in the dust.
I just find a semi-auto more comfortable to shoot than a revolver, especially the featherweight wheelguns.

[papercutter]

Livnhel

I think your better off with the .38 , as 90gr .380 fired at a big guy will just make him mad.
There are many stories of light 9mm / .380 penetrating / expanding on the surface. Thick nylon jackets act as bullet proof vests at range . Full metal jacket rounds do less damage and make a clean exit.

Look at the numbers for plus P .38 ammo ,before you throw out the snub nose 6 shooter. hollow points / wadcutters ,,,feed better in wheel guns.

["DoubleAction"]

Using the Gold Dot Hollow Point, Georgia Arms loads both the 380 ACP, and the 38 Special in their Sheer Power plus defensive loads.

The 380 ACP/ 90 gr. is 950 FPS / 180 Ft. lbs.

The 38 Special / 125 gr. +P is 1000 FPS / 277 Ft. lbs.

Using the same bullet design in a defensive application, the 38 Special offers more weight, with higher velosities, and more energy.

www.georgia-arms.com

["DoubleAction"]

klmhq said:

.40 S&W - 165 grain FMJ - 955 fps. So it's Ek is 165 x 955² or 150,484,125 grains x fps²

.357 Sig - 124 grain FMJ/FP - 1263 fps. It's Ek is 124 x 1263² or 197,800,956 grains x fps²

It is very easy to find the .40 S&W FMJ with a velosity rating of 1050 fps and muzzle energies of 400 ft. lbs., or more.

The 357 sig ( .355" Diameter bullet, same as 9mm ) in the FMJ, will easily give out 1300 fps, with 469 Ft. Lbs. of muzzle energy.

Go to the Gold Dot Hollow Point Bullets in these two cartridges, and this is a sampling of what you can expect.

.40 S&W 165 gr. H.P. + P - 1100 fps. / 443 Ft. Lbs.
.40 S&W 155 gr. H.P. + P - 1200 fps. / 495 Ft. Lbs.


357 Sig 125 gr. H.P. - 1400 fps. / 544 Ft. Lbs.

Some tests will reveal much higher velosities because these were measured at 15 feet from the muzzle.
Patrick Sweeney measured the georgia arms 357 sig, 125 gr. FMJ at 1458 FPS, which was cataloged at only 1300 FPS.

[Callahan]

Point taken, Papercutter, but it's 86.7 degrees outside temp on the ol' digital thermometer as I read this.

Those big ol' sweathogs have changed to t-shirts! ;D