What Are "True" .357 Magnum Ballistics?

G

GunXpatriot

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So you see all these .357 loads, kind of all over the place in the energy department. From like 400fpe all the way up to around 800 or 900fpe.

One loading will have 158gr at 1500+ fps.

Speer Gold dot (um, the "full size" barrel) has what, like 580 ft/pds, while the short barrel loading has only under 300 ft/pds. Now I'm 100% sure that these types of purpose-built defensive rounds are designed to get the most of the round, without devastating recoil, because of course, that would be impractical. I imagine that to be especially true with the .357 Gold Dot Short Barrel.

Come to think of it, looking at BrassFetcher's video, check out the devastation that 125gr gold dot caused. I guess then, it should be no surprise why a .357 has the highest rated stopping power among all "orthodox" handgun cartridges, or so I've heard.

Now look at that Prvi Partizan 158gr Semi-jacketed HP. Traveling at advertised 1608 fps. That's over 900 fpe. A real devastating load. So with loads like that, which seem to be safe to fire, out of any .357 magnum handgun, it makes me wonder what kind of power a .357 is really capable of, when you push to a maximum load.

It seems like most of the loads with lower energy, are simply made that way to be more orthodox with less recoil and designed with a good expanding bullet to reliably dump that energy and hopefully stop within the target, at least in theory, and at least with a well designed, well optimized expanding bullet. The 125gr Gold Dot is probably a great representation of that, I suppose.

Now I know that a different weight bullet with a proportionately different speed could generate different levels of pressure, compared to another load. That's why I'm ATTEMPTING to use energy as a gauge for power, which is not really correct at all, but just kind of ballparking it.

If loaded with a, let's say, 125gr bullet, what would the maximum safe velocity be, and what would the energy of that loading be? Now take the same with a 158gr. What would max velocity be, and how much energy would the load have?

To be honest, I always ball-parked .357 Magnum to be within the 700fpe range energy wise (which of course, isn't a great gauge of "power"), but to see loadings with significantly more energy, how high could one safely go? I imagine not much higher than that PPU, but I could be wrong.
 
Well to see what the .357 is supposed to do, look up an old copy of the SAAMI standards, from the first year of the .357s introduction.

Remember, the modern loads are tested in 10 inch vented barrels,and used in 3-4 inch barrels. Big drop there.
 
the 357 magnum has a huge difference in normal and what is possible. I have seen with my own eyes (I posted pistures) of a load that gets about 900 foot pounds of energy from a 6 inch barrel. If you would like to see it search my post on buffalo bore and the Coonan.

Most loads how ever typically run about 400-500 foot pounds.

The other thing is the 357 really comes alive from a carbine barrel. A gain of 500 FPS is not impossible. I have seen a 16 inch carbine with Buffalo bore break 2100 fps but that is not the norm. Usually from a carbine you are looking at 1600-1900 depending on the load.
 
Probably more than any other popular cartridge, the 357 Magnum can be what ever you want it to be...as long as you don't look too closely at the details.

Bullet weight makes a big difference in velocity and consequently energy. Barrel length can make a bigger difference. Water down a 357 loading to reduce recoil and you have something less than a "real" 357. Probably more like the 38/44 from the 1930s.

My point is, there is no answer to your original question of about "true" 357 Magnum Ballistics. Even the much commented on "original" performance of a 158g bullet at 1510 fps was taken from an 8-3/8" barrel. Even that same old load (not duplicated by the factories today except maybe by Buffalo Bore) is a different critter out of your 2.5" M-19.

I'll give you my take on "real" Magnum performance out of the common 4" barrel. A 125g should reach at least 1400 fps and probably a bit more. A 158g should break 1200 fps at a minimum. Again this is out of a 4" barrel but be advised, velocities can vary out of different revolvers with the same length barrel.

Dave
 
Original Winchester ballistics for the .357 were a 158-gr. bullet at roughly 1,500 fps out of an 8 3/8" barrel.

At least that's what Winchester and Smith & Wesson claimed.

True velocity was probably a bit lower.
 
Threads like this one tend to generate similar results, sometimes getting messy on the way to similar conclusions. Please note that I am not saying your thread or question or topic is a BAD one, I'm merely saying that I have seen these discussions evolve and they end up somewhat frustrating.

Here's a few things that I believe I can say with confidence -- while taking particular note to admit that I don't know much! ;)

Handguns are handguns, especially handguns that will or may be placed in a defensive role, so while it is entertaining to compare & contrast, and (again) I am not suggesting that we don't... the most valid conclusion is almost always going to be that it's a handgun, so it falls short of what we REALLY want, but even more realistic is that we simply don't know what will actually happen in any defensive shooting, and bullet placement is key and means more than all the rest. We have logged hours upon hours discussing the merits of one caliber over another, but in the real world, each instance of actually USING one of these rounds it's 100% it's own animal.

Case in point: There was a high profile defensive shooting in Florida just over a year back that involved a low-dollar Kel-Tec 9mm, running Sellier & Belot JHP and I think most of the folks in this forum who have, uhhh, HEARD of this case would agree that 9mm worked awfully well THAT time. :eek:
Well to see what the .357 is supposed to do, look up an old copy of the SAAMI standards, from the first year of the .357s introduction.
Click to expand...
I don't believe SAAMI existed in 1935. And it may be worth noting that the earliest .357 Magnum loads were lead bullet, which tend to offer less resistance going down a bore, so they tend to move a bit faster than a jacketed one (if all else is equal) and other reports concluded that you could get maybe six shots off before the barrel leaded up so badly that the accuracy went out the window. My point is that 1935 .357 load reports may not be all too relevant in this discussion -- but it is safe to suggest that .357 Magnum today doesn't match the performance of .357 Magnum from decades long gone by. It has been tamed down, for sure.

I've seen real-world chrono results from my own .357 Magnum handloads and while I've also done testing with a Coonan pistol, I think it should not be a part of this discussion because there are only two repeating handguns that I know of that run .357 Magnum from a non-revolver, which puts them at an obvious advantage with regard to velocity. The Coonan & the Desert Eagle, and I think we can agree that when we're talking .357 Magnum, generally, we are talking about a revolver.

I've recently clocked 1,319 fps from a 6-inch revolver with a 158 grain JSP handload and I'm certain that I can push it faster. I don't know how much faster, but as a handloading exercise, it's on my "to-do" list, for no reason other than the chasing of knowledge and experience. That spits out 610 ft-lbs.
 
SAAMI was founded in 1926.

A number of the powders available in 1936 are still available...

2400, and possibly several of the Du Pont/IMR Sporting Rifle powders spring immediately to mind.
 
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I did not know SAAMI has been around that long. I do know they did not rate calibers in PSI standards in 1935, and PSI has been found to be more "accurate" than the former CUP standards. And the two are not "convertible" ... I'm trying to say that you can't plug one number in to any manner of a conversion and get the other number to spit out.
 
357 ballistics are very dependent on barrel length. Most published numbers are from 7.5"-8" barrels. Problem is that few people actually use those barrel lengths with most being 3"-4". Actual numbers will be significantly lower. A 124 gr 9mm+p will match 125 gr 357 loads fired from 3" barrels and beat 357 loads from shorter barrels. But if you use heavy 180-200 gr bullets loaded up to their full potential and fire them in 6" or longer barrels and a 357 will kill any game animial in North America.

A 357 is a very versatile round that can be loaded up or down for a wide variety of uses.
 
My data comes from my chronograph. So all my numbers are "True".

Out of a 6" barrel I got a 125 Speer Gold Dot to do 1647 fps or 750ft/lbs.

Out of a 18.5" barrel I got a 125 XTP to go 2,227 fps or 1,376 ft/lbs.

Both are handloads.

I have lots of real data. PM me with your email address if you want the spreadsheet.
 
Steve... Out of an 18.5 inch barrel, that is a potent load. I didn't think that kind of increase in velocity were possible!

If that 6 inch barrel were a semi-auto pistol like a Desert Eagle, I bet there'd still be room for improvement, but yeah, that would be kind of "unorthodox". Those are the kinds of numbers I was looking for. I'll PM you. Thanks.
 
Actually, thanks for that Tipoc.

You know, like Dave said, velocity varies out of the same length barrel for a different revolver.

The Korth 6" was consistently getting 100fps faster than the Colt Python 6".

Now I'm kind of a noob, but what exactly causes this? I would imagine this is caused by (maybe) a larger cylinder gap? I suppose that even with a gap slightly larger, you're losing pressure in basically every direction, rather than a small hole for a gas system.

Like I said, it makes you think about how a 6" desert eagle would perform, and I'd imagine, quite a bit better than both of what I mentioned.

So I guess in that sense, revolvers are a little "outdated", but hey, they look cool, they work, and are time-proven, so they will always have a place in that way, which is a given. That, and the fact that a 6" Desert Eagle doesn't seem like the easiest gun to carry, even with a notable increase in ballistic performance.


At the same time though, that means that even the guns designed for these types of cartridges, really can't even have the perform to their fullest. But going off that... It seems that every recoil calculator I look at requires a charge of powder. I thought this was more up to velocity and bullet weight...

So, suppose the Korth and Python are the exact same weight, hypothetically. Let's ignore grip angle, etc for a second, although, the recoil energy would techically be the same, the grip angle can kind of push on the wrist or hand, etc. Not so important though. With 100 fps more, would recoil be any different? It's really hypothetical, but it makes me wonder still, why amount of powder in the charge matters, versus perhaps burn speed, or specific type of powder.
 
Gun X. A Python is a bit "slower" than most due to a tighter bore. As a side effect they are also a bit more accurate than most. A "true" 357 Magnum does not recoil that badly out of a full size revolver, they just take practice to master.
 
Its a known fact that different guns will shoot the same ammo at slightly different speeds. Usually the difference is fairly small, but a difference of 100fps while uncommon, is not rare.

And its due to ALL the factors involved, barrel cylinder gap, bore friction, and others.

I had a clear demonstration of this at one time. A friend brought over some ammo that I had loaded for him sometime earlier, a 125jhp, and a case full of 2400. This ammo was intended for his Marlin carbine. We fired it through three pistols and the carbine, over a chronograph. Keep in mind this was a hot load, intended for the carbine.

First gun, S&W Model 19, 6" barrel.
My friend was shooting (it was his gun), and he did something I had never seen before, he literally, got the gun to double. Two rounds were fired, instead of one. I had heard of that happening (rarely) with a .44 Mag, but never with a .357!:eek:

At that point, we decided to stop shooting that ammo in the M19. The cylinder opened normally, but we had to use a wood dowel and a small hammer to get the two fired cases out.

Chrony said 1620fps.

Second gun, S&W Model 28-2 6" barrel
6 rnds fired normally (including the unfired rounds from the M19)
Slight resistance, then ejected normally.
Chrony said 1670fps (avg)

Third gun, .357 Magnum Desert Eagle 6" barrel
This was one of the early (pre Mark I guns and had polygonal rifling)
9 rnds fired (full magazine)
Flawless function.
Chrony said 1720fps (avg)

Marlin .357 Carbine 18.5" barrel
9 rnds fired (full tube)
Flawless function
Chrony said 2200fps (avg)

Now, that 100fps difference between the fastest and slowest handguns and almost 500fps gain from the carbine over the fastest handgun. The down side of the carbine speed is that the regular 125gr JHP is radically overdriven, and at that high speed tends to act like a varmint bullet. It literally explodes when it hits something. Penetration is ....poor.:eek::eek:

The original claims for the .357 Magnum were the 158gr at 1550fps from the 8 3/8" barrel S&W Registered Magnum. I read a report, done in the 70s, where a few rounds of "white box" .357 were tested through an 8 3/8" S&W. (White box at the time referred to the early production ammo used for testing and development before the factory geared up to mass produce labeled ammo. NOT the generic "white box" ammo you get at Walmart today. Not even.)

Allowing for the variance of individual guns, the ammo was in the 1500fps range. Also 6 rounds were fired through a model 66. The cases required a mallet to remove.

Original level .357 Magnum loads are simply TOO HOT for a K frame revolver. I believe that is the primary reason that the .357 has been downloaded from its 1935 level. Lightening the load a bit still provides a significant increase over the 38 special, and allows it in a much wider range of guns.

As to why the recoil calculators as for the amount of powder, its because they are calculating everything that figures into the recoil energy. The amount of powder that turns into gas, and ejects from the muzzle (at around 4000fps) has energy. Not a lot of mass, but very high speed, and it is enough to measure and figure into the calculations. You and I won't notice the difference but a calculator can.
 
if you go back to an old Speer reloading manual they chronograph several 357 loads in quite a few different revolvers and there was a lot variance. I don't remember the manual but the article was called "Why Ballistians Turn Gray."
 
A 125 JSP might be just the ticket out of a carbine. To keep it from exploding.
The SGD's are bonded so I don't think it would fragment anyway.

I get the best accuracy with hot 125's out of my 77/357 bolt gun.
 
If loaded with a, let's say, 125gr bullet, what would the maximum safe velocity be, and what would the energy of that loading be? Now take the same with a 158gr. What would max velocity be, and how much energy would the load have?
Click to expand...
As others have noted, the chamber pressure and not the velocity governs what is safe. Buffalo Bore is known for near maximum pressure/velocity loads. They list a 125 gr. load with a muzzle velocity of 1700 fps and energy of 802 foot pounds out of a six inch Ruger. Their 158 gr. load has a muzzle velocity of 1,475 fps and energy of 763 foot pounds out of unidentified barrel, though they do list several guns they used with similar results. https://www.buffalobore.com/index.php?l=product_list&c=20
 
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