.357 magnum VS .38 spl question

Discussion in 'Ammunition & Reloading' started by kirbinster, May 17, 2013.

  1. kirbinster

    kirbinster New Member

    I recently purchased a S&W686+ 4" stainless and love my new revolver. The first day I tried it I used some .38 special and said to myself wow this thing feels like shooting a .22 - almost no recoil just a slight push. The next time out I tried some .357 magnum and wow, the thing kicked and I really felt it in my hand. So, my question is how can there be so much difference in these two rounds that are the same diameter and only differ in length by roughly 1/10th of an inch. Both sets of rounds were from the same manufacture and were both 158 grains - so how do they stuff so much more power into that 1/10th of an inch? I looked up the energy difference and the .38spl is rated at 285 while the .357 mag is shown as close to double that at 548.
  2. 95sniper

    95sniper New Member

    Different powder charges, ect. I'm not an expert on this though.

  3. kirbinster

    kirbinster New Member

    Can someone elaborate on this? I am a newbie and just assumed gun powder was gun powder -- I guess not.
  4. nitestalker

    nitestalker New Member

    Not recommended but a .38 Special can be loaded to near .357 Magnum pressure levels. The .357 Mag. was produced in longer cases to keep it from being fired in .38 Special revolvers.
    You may also look at the ballistics of .38 Special Plus P ammo.:)
  5. TekGreg

    TekGreg Lifetime Supporting Member Lifetime Supporter

    Fast burning vs. slow burning powder, magnum primers, form of powder (pellet, disc, etc.) all have a effect. SAAMI (Sporting Arms and Ammunition Manufacturers' Institute) sets the power levels that manufacturers must stay under for safe usage. .38 spl is a very old caliber, and even some older revolvers that were originally chambered for .38 spl must now use .38 short because pressure levels have continually risen over the years. .357 mag is a relatively recent chambering (compared to .38 spl) so the pressures are allowed to be much higher because manufacturers of .357mag handguns took these pressures into account. This is why a handgun chambered for ONLY .38 spl is usually much lighter in weight than a .38/.357 handgun such as yours - it doesn't need as much metal to handle only the lighter round.

    So, basically, the .38 is loaded to a much lower standard, where the .357 has a lot of powder pushing the exact same bullet. The length of the case is only a safety feature to keep people from chambering a .357 mag in a gun only intended for .38 spl - it has no bearing on how much powder is actually used.
    Last edited: May 17, 2013
  6. JW357

    JW357 New Member

    I'm no expert but at the very least 357s use "magnum" primers which I assume have more umph to them. I'm sure the powder is also different.

    There are all sorts of powder. Some burn cleaner or dirtier, some faster or slower. I don't yet reload for 357 so I can't tell the best to use for the hotter loads. But as an example, with even just half a grain extra in powder, you will feel the recoil more substantially. I imagine you could get a fair amount of powder in that extra tenth of an inch or so.
  7. Overkill0084

    Overkill0084 Active Member

    The standard .38 Special has a Max pressure of 17,000 psi. The .38 Special +P is rated at a max pressure of 20,000 psi.
    The .357 Magnum has a max pressure of 35,000 psi.
    The extra 1/10th of an inch has two functions:
    1. It prevents loading a .357 cartridge into a .38 special camber.
    2. It increases powder capacity, allowing for stouter charges.

    Gun powders are products engineered to exacting tolerances for specific applications. Do some research into reloading and you can learn all the ins & outs of various powders. There are hundreds of powders available to the consumer, and probably as many again, that are not.
    Even if you have no immediate plans to start reloading, learning about the variables and processes involved will give a better understanding of why things are the way they are.
    Last edited: May 17, 2013
  8. John_Deer

    John_Deer New Member

    Most 357mag loads are pretty hefty. If you look at a reloading manual 9.* grains is a starting load. The max load being well over 10 gr of powder. PPU factory ammo has 10.2 grains of powder under a 158 gr bullet.
  9. nitestalker

    nitestalker New Member

    The .357 Magnum grew out of "Hot" .38 Special loads. The S&W 38-44 large frame revolvers allowed .38 Special loads in the 30,000 PSI range in the 1920s. In 1937 S&W legitimized the hot .38s with the heavy frame Mdl. 27 in an elongated .38 Special case.
    The popular load of the day was 16 grs. of 2400 powder under a 158 grs. bullet. There were no magnum primers in the day. Small rifle primers were used to contain the sever back pressures.;)
  10. robocop10mm

    robocop10mm Lifetime Supporting Member Lifetime Supporter

    Twice the pressure, twice the energy, twice the recoil. Kind of like the difference between a car with a 200 HP engine and the same one with a 400 HP engine. Night and day.
  11. c3shooter

    c3shooter Administrator Staff Member

    Just to add some history- .38 Special, born in 1899, originally loaded with 21 grains of black powder. That is why you have the volume of a .38 Spec case- black powder had to completely fill the case right up to the bullet.

    But when they changed to smokeless, it fills only a small percentage of the case. And unlike black powder, it is ok to do that. It would be POSSIBLE to put about 8-9 grains of Bulleye powder in a .38 Special case- a VERY DANGEROUS triple overload.

    When the .357 Magnum was created in 1935, they started with a heavier framed handgun, a catridge case just a smidge longer so you could not accidentally put it in a .38 Special- and then they used the available space in that cartridge case.

    And no, gunpowder is NOT gunpowder- there are different powders that have different burn rates, different pressures- and it is rare to have a smokeless powder that completely fills the case.

    THAT is why reloaders have scales, and reloading manuals- you have to match the correct amount and type of powder to the weight (and design) of the bullet for THAT caliber- otherwise you will destroy a gun, hurt yourself and innocent bystanders.
  12. onenut58

    onenut58 New Member

    Back in the thirties there were gangsters using serious fire power Clyde Barrow was the worst. He robbed national guard armories and stole browning automatic rifles. We all know they were chambered in 30-06.
    He could rob a bank and jump in one of the old flat heads v-8 fords he chose to steal that would out run all cop cars.
    He had a weapon that would go right through any car made and full auto fire power.
    Back in the thirties most cops carried 32 caliber handguns and a few carried the 38 special.
    One of the problems with a 38 special is they would not go through the cars of the day and a cop could not shoot a gangster through the door.
    Smith and Wesson took a N frame 44 special that is a much heftier gun than a k frame model 10 and chambered it in 38 special and called it a 38/44. They then could shoot very hot 38 special close to the ballistics of todays way tamed down factory spec ammo of today.
    The same time they did this they were working with Remington to develop a even more powerful load for the 38.
    Using a specialy heat treated 38/44 they came up with the 357 magnum load.
    Smith and Wesson desighned a new N frame revolver called the registered magnum that was also heat treated and the cylinders reamed deeper to accept the longer cartridge.
    These guns were hand made and had to be ordered. They could not be bought off the shelf in a gun store.
    Each gun was registered with smith and Wesson and the owner received his registration for his new custom gun.
    The year was 1935 and J edgar Hoover received the first one.
    They came with different barrel lengths and site configurations depending on what the buyer ordered.The standard ammo of the time for them was 1400 feet per second at the muzzle.
    The term magnum they used to name the new cartridge came from French wine bottles that were over sized called magnums.
    At the time there were many k frame 38 specials not capable of the pressures the 357 magnum produced so the 357 magnum was made with a longer case so it could not be loaded into any of these.
    Many of the 38/44 guns were around and some had the cylinder reamed to accept the 357 magnum and people fired them through them.
    The old 38/44 handled them but was not as strong as registered magnum that was the great grandpa of the model 27.
    Over at smith and Wesson forums there is a member called SaxonPig who is a college professor and smith and Wesson collector.
    He has a article he wrote and put in the faqs section on +P ammo.
    It is a very interesting read well researched with testing he did on the old standard ammo for 38 special and 357 magnum that was considerably hotter than todays factory offerings in the +p.
    He posts his results testing some of the actual older ammo.He explains how cheap imported guns started arriving in numbers in the usa that were weak compared to the popular colts and smith and wessons and the ammo companies feared law suits from there ammo blowing up these cheap guns.So they cut the loads way down and invented the +P
    In the seventies you could still buy smith and Wesson ammo that was considerably hotter than todays +p rated ammo as standard ammo for there guns.
    The older members here who shot that ammo I am sure can recall it was pretty hot compared to other manufacturers.
    I shot a considerable amount of that ammo back in the seventies through my model 27
    The question of difference in 38 and 357 is the powder used. All loads are based on how much pressure it produces in the case to push the bullet to certain velocities.How fast or slow this powder burns building up pressure before the bullet is forced down the barrel.
    Different powders burn faster slower and different amounts of powder can produce higher or lower pressures.
    That is why there are reloading manuals that give those very important specs for particular powders and maximum pressures allowed in particular calibers etc.
    In 1955 smith and Wesson came out with two new guns the 44 magnum that later was called the model 29 and a new version of the model 10. Metallurgy reached a point where smith and Wesson could heat treat a K frame 38 today known as model tens to be able to handle the 357 magnum.
    They put ribbed barrels on them and called them the model 19 and fixed sight versions were the model 13. Stainless later versions were the model 66 and fixed site model 65.
    Any smith and Wesson made after 1920 can fire +p ammo due to the then heat treating reached a level of strength to handle the hotter than +p standard loads of the day.
    Although I have been shooting since I was big enough to hold a gun I had never fired a 38 until two years ago when my brother in law brought along a model ten heavy barrel for plinking.
    He had +p factory ammo and I was amazed at how it was like shooting a 22 that had a little more muzzle jump. Virtualy no recoil.I have never bought or had a urge to shoot 38 through my 357 magnums.I still don't know what a standard 38 feels like and don't feel like wasting money to buy any and fire them through one of my model 27.
    The recoil of a 357 magnum in a model 27 is so light I cannot picture or get my mind around why people do it as well as having to scrub out the cylinder of powder residue.
    How ever I do own a colt cobra that I have never fired left to me by my dad he used in his retirement job as a security guard.
    My mother uses it for her night stand.
  13. nitestalker

    nitestalker New Member

    Yes but Bonnie and Clyde would meet their end with a Browning Automatic Rifle 30-06. I don't recall a Mdl. 27 at that party.:D