357 mag. vs 9mm

Originally posted by Nanuk:

Actually it is @ 500 FPS difference. I consider that a significant increase. I believe it is needed for SD, but I have seen lots of folks shot
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I've yet to achieve a full 500fps difference from my .38 loads and my .357 mag loads outta the same revolver(maybe cause I don't load .357 hot), but still consider 400fps significant when it's 50% faster. For hunting deer, or for defense against 4 legged predators, I feel that difference is needed. For military and tactical police work, again, yes. Outta a CWC used primarily for SD at close range against two legged predators, I do not. That does not mean I don't respect your opinion that you need it. Everyone should use what they feel is appropriate for the scenarios they may encounter.
 
Auto pistol ammunition has to operate within a specific pressure/velocity range; the gun is the limiting factor. Ammunition for revolvers has no such limitations (as long as the bullet will exit the barrel and the gun does not blow up), so it can be much more flexible.

Jim
 
How about this, you get a 2" 9mm revolver and a 2" .357 Mag revolver, and chronograph them side by side with a variety of loads.

I think that will definitively settle the matter.
;)

And don't get me started on how the ammo makers have "wimped out" the .357 mag. Still, even with factory loads, 850fps from the .38 vs 1300+fps from the .357 (same gun) is, to me, still a significant difference.
 
The original question was about both rounds used in a revolver, shouldn't even be close in the 357's favor.
 
I have been loading up the SP101 2 1/4" with Underwood 125gr 357 magnum that is rated at 1500fps out of a 3" barrel. Underwood's fps is often underrepresented as well. Hot stuff. I dont think the 9mm 124gr +P is even close to that out of my Kahr CM9.
 
Really? You think when you drop the 9mm to a 2" barrel with a cylinder gap it will preform equal to the 357?
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If you stick to commercial loads, there is reason to believe the results will be in the same ballpark. Using a two inch test barrel (no gap), Ballistics by the Inch reports:

.357 mag Corbon 125 gr.JHP = 904 fps
9mm Corbon 125 gr JHP +P = 1061 fps

.357 mag Corbon 110 gr. JHP = 928 fps
9mm Corbon 115 gr. DPX = 1132 fps

.357 mag Federal 125 gr JHP = 949 fps
9mm Federal 124 gr. Hydra-Shok = 900 fps

Both calibers would lose some velocity with a cylinder gap but I would think it would be pretty close to the same loss due to similar bullet weights.

Obviously, if you hand load, I would expect you to be able to get a whole lot more from a .357 from a short barrel than from a 9mm. However, sticking with common commercially available offerings, the 9mm is often in the same ballpark as even .357 magnum from a short barrel. It has the advantage of lower recoil and less flash.
 
KyJim said:
If you stick to commercial loads, there is reason to believe the results will be in the same ballpark. Using a two inch test barrel (no gap), Ballistics by the Inch reports:



.357 mag Corbon 125 gr.JHP = 904 fps

9mm Corbon 125 gr JHP +P = 1061 fps



.357 mag Corbon 110 gr. JHP = 928 fps

9mm Corbon 115 gr. DPX = 1132 fps



.357 mag Federal 125 gr JHP = 949 fps

9mm Federal 124 gr. Hydra-Shok = 900 fps



Both calibers would lose some velocity with a cylinder gap but I would think it would be pretty close to the same loss due to similar bullet weights.



Obviously, if you hand load, I would expect you to be able to get a whole lot more from a .357 from a short barrel than from a 9mm. However, sticking with common commercially available offerings, the 9mm is often in the same ballpark as even .357 magnum from a short barrel. It has the advantage of lower recoil and less flash.
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It still depends on the loads. It's easy to cherry pick loads that show one on the low side and another on the high side.

Showing 125gr 357 at 900fps is a prime example of doing this. Even from a 2" barrel that is a very anemic load.
 
the 9mm is often in the same ballpark as even .357 magnum from a short barrel. It has the advantage of lower recoil and less flash.
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Ok, the flash part I get, the .357, loaded with more, and slower burning powder than the 9mm will give much more flash in a short barrel.

But, if you are claiming essentially similar bullet weights, at similar velocities, how can the recoil be anything but essentially the same?

Personally I don't put a lot of stock in anyone's published data, online, or otherwise, to tell me exactly what happens in my guns. I'm sure its quite accurate for what happens in their guns, but their guns aren't my guns, nor are they your guns.

Fine for generalities, usually, but individual guns can be very individual, or they can follow the general trend. The only way you know exactly what is happening is to test the gun in your hands.

Particularly when you are looking at what are, essentially very small difference in velocity in handgun rounds. I've seen 100fps difference between three guns all shooting the same ammo out of the same barrel length.

I've seen shorter barrel guns shoot faster than longer barrel ones. Rare, but it can happen. There are just too many variables between the guns and ammo tested for the published data, and the gun in your, or my hands to take their data as anything more than a general guideline, one for which drastic exceptions can, and do exist.
 
For those quoting BBTI's numbers, please bear this in mind:

One note: in every case with the T/C Encore the length of the barrel was measured from the end of the barrel back to the breech face. This is how semi-auto pistols are measured, but revolvers are measured as the length of the barrel in front of the cylinder gap. Take this into consideration when comparing calibers using our numbers.
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http://ballisticsbytheinch.com/calibers.html

Because the maximum OAL for a .357 Magnum's case is 1.59", BBTI's 2" barrel numbers for the cartridge are, due to the way the T/C Encore barrels were measured, the functional equivalent of a revolver with a 0.41" barrel. I am aware of no production .357 Magnum revolver with a barrel less than half an inch long, so BBTI's 2" barrel .357 Magnum numbers are pretty meaningless as anything but a curiosity.

As a matter of fact, there are only three cartridges tested by BBTI that are really comparable to real-world guns from their 2" T/C Encore barrels. .22 Long Rifle, .22 Magnum, and .25 Auto are the only three cartridges tested by BBTI that are commonly available in guns with barrels short enough to be comparable to their 2" test barrels. Pretty much everything else from .32 Auto up is only commonly found in a gun with a longer barrel.
 
Great point Webley, funny how ballistics from actual revolvers differ so much from this velocity test.
 
I posted numbers for 9mm revolver chronograph results in post #8.

I was thinking about getting one of my 2.5 inch .357 magnums converted to 38 super, which would also shoot 9mm, so I've been doing a lot of research on this topic. Also, Ruger is now making the LCR in 9mm, so that's an easy factory solution. In the end it didn't seem to be worth the trouble to buy the Ruger (don't like the LCR anyway, owned one and sold one already) or covert my current revolver.

I think we're all getting wraped around the axle about a particular load. The 125 grain .357 mag is great form a 4 inch gun, but has a lot of blast and flash from a short barrel revolver. In a snub, it loses a lot of velocity and chronographs similar to a 9mm +P from the same revolver.

However, when you start looking at loads that are 140 grains and over, the .357 magnum isn't losing much from a short barrel.

Case in point...

147 grain 9mm from the LCR - 990 fps
140 grain .357 from LCR - 1185 fps

For power and performance from a short barrel, it seems to me that the 158 grain .357 magnums might be the best choice. Even generic loads will often chronograph near 1100 fps or greater from a short barrel. If I want a more moderate load, then there are some hot loaded 158 grain .38 special +P or +P+ loads.

Advantages to the 9mm LCR is sharing ammo with another handgun or in between loads, especially with 115 and 125 grain bullets. Also, probably faster to load from a moonclip because of the shorter case.

Ruger 9mm LCR numbers...
http://www.gunblast.com/Ruger-LCR9mm.htm

Short barrel .357...
http://www.snubnose.info/docs/38-snub_vs_357-snub.htm

Ruger .357 LCR numbers
http://www.personaldefenseworld.com/...#198-ruger-lcr
 
But, if you are claiming essentially similar bullet weights, at similar velocities, how can the recoil be anything but essentially the same?
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You are forgetting the mass of gasses, unburnt powder, and anything else leaving the barrel. Those have to be figured into recoil.

It still depends on the loads. It's easy to cherry pick loads that show one on the low side and another on the high side.

Showing 125gr 357 at 900fps is a prime example of doing this. Even from a 2" barrel that is a very anemic load.
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I didn't cherry pick. I picked the loads with similar bullet weights from the same manufacturer to be as close as possible. As I said, if you handload, it's a different story.

Because the maximum OAL for a .357 Magnum's case is 1.59", BBTI's 2" barrel numbers for the cartridge are, due to the way the T/C Encore barrels were measured, the functional equivalent of a revolver with a 0.41" barrel. I am aware of no production .357 Magnum revolver with a barrel less than half an inch long, so BBTI's 2" barrel .357 Magnum numbers are pretty meaningless as anything but a curiosity.
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A valid point. However, you then have to use the overall length of a 9mm cartridge which is .754 inches which means that you add another 3/4 inches to the "barrel length" when shooting from the equivalent in .357.

Let's use a 3.5" TC barrel length to correspond to a snubby. BBI doesn't have that length but we can extrapolate. The 125 gr. .357 magnum from Corbon is 1496 fps from four inches and 1257 fps from three inches. So, the extrapolated value is 1376 fps.

Let's take a look at the 9mm +P 125 gr. from Corbon. Here, though, we add 3/4 inch and look at it as if fired from a barrel length of 4.25 inches. The extrapolated value is 1282 fps. Thus, there is about a 100 fps advantage to the .357.

How significant is a 100 fps advantage using modern ammo? I don't think this will be a significant advantage. And I previously mentioned flash and recoil.
 
Extrapolations of data are meaningless. You are taking best guesses.

Using weak watered down 357 loads is in fact cherry picking. It doesn't matter to me if the 9mm loads are from the same manufacturer or not.

If you really think the 9 mm is in par with the 357 mag out of the same length barrel, more power to you. You certainly aren't going to convince many others of your belief.
 
Who has a T/C in .357 Mag with a 2" barrel and how does it relate to a revolver with a 2" barrel? We may as well be arguing about weather the Millenium Falcon could shoot down the Starship Enterprise.
 
When you shoot 9mm out of a revolver with a 38Spl or 357 length cylinder some very odd things happen that gives the 9mm an artificial velocity boost from an unexpected source. It won't match a 357 but for personal defense purposes it'll come "close enough".

Here's what everybody misses: the inside of each cylinder bore in a 9mm or 45ACP wheelgun is cut very differently from a 357 or 38Spl.

The 9mm chamber has a "lip" inside that the forward edge of the shell rests on. The chamber in front of that lip is a dead straight smoothbore of either .355", .356" or you can split the difference with .3555". There's no constriction at the end of the chamber like there is in a 357. Once fired the slug travels through this 3/4" or so tight smoothbore space with more or less no blow-by at all. It is then going like a bat outta hell when it hits the gap and the back of the barrel. You then need a good quality barrel to grab that abnormally-fast-moving slug and put a spin on the damn thing.

The round gains a lot of speed in that long straight smooth "throat" in the latter half of the cylinder. This setup is actually very nice for a small combat wheelgun. It's not so nice for peak accuracy, so for example S&W's competition-oriented 8-shot 9mmPara built on the N frame has a very short cylinder and the barrel is set back some to match.

When I converted my daily carry wheelgun from 357 to 9mm I took full advantage of this peculiarity. I used a Bowen oversize cylinder blank cut in 9mmPara with long throats done with a .3555" chucking reamer for even more of this "long throat" speed boost, and coupled that to a Douglas Premium barrel of only 3.25" (plus another 1/2" or so for the gas trap). I haven't chronographed the results yet but I think it'll spit combat loads very fast, and that big Bowen Cromoly cylinder (Ruger New Vaquero) should be able to soak up as much +P and +P+ as I can afford given that it can cope with 41Magnum (as a six-shot) just fine.
 
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