10mm v .357 magnum

Discussion in 'Caliber Corner' started by vandros, Jan 26, 2013.

  1. vandros

    vandros 10mm fan

    Hi all! What are some important theoretical and practical differences between performance of these two calibers? It seems when bullet weight and velocity are equal, their ballistic characteristics are VERY similar. What are your thoughts/experiences?

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    #1 vandros, Jan 26, 2013
    Last edited: Jan 26, 2013
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  3. Generally the 10mm is a semiauto and the 357 mag is a revolver. I think there's more difference between the guns than the claibers.

    If I could jut have one pistol? I guess i'd flip a coin. No wait! I'd take take the S&W model 1006 unless I could have a brand new 5" Colt Phyton :)


    #2 rustytxrx, Jan 26, 2013
    Last edited: Jan 26, 2013
  4. Allot of arm chair ballistic techs will tell you these are equal...Well, they aint!

    The missing equation is the .401 bullet vs .357 Bullet. In bullets on game, bigger means better. In terms of faster incapacitation.
    Then there is both calibers loaded to SAMI spec for each. That 35K for the Mag and 37K for the 10mm. The 10 is notoriously loaded lite for all the ''ahem'' recoil sensitive folks who couldn't handle the round.
    Then both need to be shot thru a same length barrel and finally both thru either a vented or non vented barrel. NOW we have a level playing field to compare them.

    The 357 fired from a 10'' Barrel will get a 110g bullet to 1750fps and a 180g to 1300fps

    The 10MM fired from a 6'' barrel will reach 1700fps with a 135g and 1250fps with a 220g.

    That puts the 10 firmly into the lower end of the 41 Magnum with a 170g @ 12500fps. IF the 41 is shot from same barrel, style and SAMI max pressure.

    #3 Cwlongshot, Jan 26, 2013
    Last edited: Jan 26, 2013
  5. folks have missed the original goal of the 10mm, which is a shame. It as originally suggested to throw a .40 cal 200 (or heavier) grain bullet at over 1,000 fps, with "heavy loads" at around 1,200. This is actually what Elmer Keith wanted when he and others proposed the .41 mag for police use (Well, a bit faster than they asked for in Police loads) which , in ballistics, was one place where Keith and Jeff Cooper actually agreed on a useful load.
  6. Comparing the .357 magnum to a 10mm is like comparing an El Camino to an F-350 4x4. Sure, they both have four wheels, a pickup bed, and can haul sheets of plywood, but one is capable of much more when used to its full potential. The 10mm can do anything the .357 can do, as well as do SO MUCH more if you want it to. Sure, you can load a 10mm down to .357 magnum performance levels, but you can also load it up to .41 magnum performance and be within SAAMI spec, or you can go a little "over book" and be solidly into .44 magnum territory. Set up with a fully supported chamber and loaded properly, a 10mm can chuck 200gr hardcast lead at 1400-1450 fps without getting pressure signs. You CAN'T do that with a .357.
    #5 blk69stang, Jan 26, 2013
    Last edited: Jan 26, 2013
  7. SDGlock23

    SDGlock23 Glockoholic

    I no longer have a .357 Mag or 10mm, but when I had the 6" GP100 .357, some of the warmer handloads I can remember off the top of my head included a 125gr JHP @ ~1700 fps, a 158gr hardcast at around 1530 fps and a 180gr XTP @ around 1325 fps. Some factory 125gr .357's are fairly warm, the Remington 125gr JHP does almost 1600 fps from a 6" GP100. The .357 loads I used were with book charges, where a number of "warm" 10mm loads aren't.

    I prefer larger bullets myself, but the higher sectional density of the .357 bullets will give them the edge in penetration, a 180gr .357 has higher sectional density than a 220gr 10mm, and there are 200gr .357's too. Then there are 16-24" barreled lever action .357's too which take it up to the next level as well, something you don't get with the 10mm.

    The 10mm is loaded "lite" but so are most cartridges from the big ammo makers, and I know a 10mm can shoot a 220gr @ close to 1250 fps from a long barrel, I've personally done it, but it's an over pressure load any way you slice it. However, I load that way too in my setup, I'm just saying that often "full power" 10mm is also "over pressure" 10mm. I would say the .357 Mag and 10mm compare favorably to one another, .40 too when you throw in a 6" bbl. I wouldn't put the 10mm in .41 Mag territory myself.
  8. I agree. the 10mm is no .41 mag at the top end. they shake hands at a very useful level but it wasn't designed to be a magnum nor was it developed to win velocity awards with light bullets
  9. SDGlock23

    SDGlock23 Glockoholic

    You will never load a 10mm to .41 Mag levels and remain within SAAMI spec, never. Reaching 44 Mag levels is a pipe dream. Both not only punch bigger holes but can shoot heavier bullets faster than the 10mm can dream of. The 10 is a good cartridge, but I begin to wonder the hype hasn't gone to some peoples heads.
  10. Of course you can't stay within SAAMI spec on the 10 and get massiver performance. Those specs are VERY conservative for a cartridge that was DESIGNED to handle much higher pressures than SAAMI spec'd it at. To clarify, the 10mm handles overspec loads because the spec is set way lower that the cartidge was DESIGNED for. The 357 OTOH is spec'd right about at the same level as it was designed for, so the SAAMI spec is a much more "hard and fast" value.

    Ballistics101.com lists the following 44 magnum load:

    240gr Federal Hydra-Shok @ 1210fps for 780 ft/lbs of energy.

    My 200gr Hardcast 10mm loads go 1400 fps for 870 ft/lbs while only being about 5% over book. I can go a *little* hotter and coax it up to 1450 fps before the primers start to flatten and get 933 ft-lbs.

    Not saying that the 10 can beat every 44 magnum load, just that it can get up into 44 mag territory, which the .357 won't with a 5" or shorter barrel AND maintain the same safety margin.

    Or, to put it another way, my loads deliver more energy than 36 out of the 74 loads on ballistics101.com for the 44M that have muzzle energy listed. That puts my 10mm loads in the 48th percentile of the loads listed, or roughly midway into 44 magnum territory. When you consider that the 44 magnum loads are tested with barrels much longer than the 4.6" glock barrel, that's sayin' something.

    Is the 10mm a 44 magnum? Hell no. Is it capable of MUCH more horsepower than a 357? Hell yes.

    Just sayin'.
  11. Bear in mind, no matter what you may think the cartridge was designed or originally intended for, the manufacturers of the guns may not agree with your optimism, nor shared it when they were spec'ing out their gun designs.
  12. I admire your bravery, but Ive got enough scars and would rather avoid anymore on my hands. Ive got a 10mm Kimber coming in tuesday and will be handloading for it, but your loads would scare the **** out of me.:supergrin:

  13. I realized years ago that trying to explain this to the 10mm extremists is akin to trying to convince a Hell's Angel that they need to wear a helmet.
  14. Berto

    Berto woo woo

    .357 mag can do 10mm and vice versa. One will bring up 6" supported bbls and nuke handloads, the other brings up 353 Casull. Neither lives up to solid 41 or 44mag loads.
  15. Couple of things...
    The velocities your velocity quotes are substantially higher that I have achieved with any revolver. Heck they are higher than most of my 10'' Contender barrel to... They are FIRMLY into some of my 357 MAXIMUM Contender and Magnum CARBINE velocities!! :wow:
    IMHO, you simply will never get to them from a vented revolver barrel while keeping at or under 35K! Even thru a 357Mag Cassul, with its extremely tight cylinder gap and quality barrel only gains me 75 or so fps over other loadings... Back when the 357 was introduced, in '35. it got these kind of velocities. But we now know that they where extremely over loaded. :upeyes:

    As for the better SD of the 357 with a 180g at just over .200 and the 220g .40 at the high .180's your correct. But its mighty close. :whistling:

    You see the 357 is limited to 35k while the 10mm is 37.5K

    I don't put the 10MM in the 44Mag class, not by a long shot. :whistling: But it absolutely is shaking hands with the LOWER end of 41 Mag loadings! All while making a more manageable package.

    I did not mention something that 69 stang brought up. Supported chambers. YES, The velocities I have quoted for the 10mm I would NOT FEEL SAFE shooting from my Delta Elites!! But they are just fine in my Glock 20 with after market barrels. Before anyone picks on this point remember, the 357 Mag is also in a fully supported barrel.. In again keeping with a apples to apples comparison...:supergrin:quoted velocities have been choreographed threw any different guns barrel lengths and styles over many years and different factory and hand loadings.

    I like the 357 Mag very much, I have hunted with it in revolvers, Contenders and Carbine rifles accounting for more than a couple Whitetails thru the years. The 10MM is a newer arrival and I took to it with a Delta Elite first, Than a second in Gold Cup guise and lastly a Glock 20 in the late 1990's. I firer a number of boxes of the Norma 170 and 200g offerings they that first Delta... Most of that brass was ruined with smiles :wow:...surely loaded above SAAMI pressure 37.5K.

  16. Berto

    Berto woo woo

    The velocities he quoted can be had in factory ammo.


    Buffalo Bore isn't noted for fudging their numbers, either.

    With 'nuke' handloads, .357 has a trick or two up it's sleave as well, since the brass can take 60K psi. (ie: 200gr/1500fps)


    I have both rounds in my collection, I consider them equals for all practical purposes.
  17. SDGlock23

    SDGlock23 Glockoholic

    As to whether the 10mm was designed to handle "much" higher pressures than it's spec'd at, I'm sure that could be argued all day long, but I see no evidence of it. Now can it handle higher pressures than 37.5K? Sure it can, but that depends on a lot of things. The .40 can handle higher pressure also, so can the .45 ACP, etc. in the right setup. If anything the .40 could handle higher pressure than the 10mm because it's got a slightly stronger case. Could the same thing be said of the .40, that's it's designed to handle much higher pressure just like the 10mm? Yet I have a feeling you might tell me the 10mm will stomp a hole in the .40, which isn't quite the case. There isn't nearly as much difference in the 10mm and .357 Mag as you think.

    I know it's easy to cherry pick loads, and that yes you could compare a very low powered, light weight reduced recoil .41/44 Magnum load to a hot 10mm, but as you know that doesn't make them in any way similar as a whole. As you should also know, energy itself isn't a good way to compare cartridges. I could cherry pick .40's that give over 800, even over 1,000 ft-lbs of muzzle energy. Yet in no way would I compare it to any .40+ caliber magnum class revolver that will shoot bigger and heavier, sometimes MUCH heavier bullets. As a whole I see the 10mm being much more similar to the .357 Mag and even it's sibling .40 S&W than with the bigger .41 Magnum.

    As for your 200gr hardcast at 1400, I'm sure the pressure is well above 37.5K PSI and your barrel longer than 4.6". I've never seen any manufacturers load data claim anywhere near that speed for a 200gr in any length barrel, and yes I question that your load is a mere 5% over book.

    Even taking your word for it, what's the point of driving a hardcast non-expanding bullet to the max? Lets take a 200gr WFNGC moving along at 1200 fps from a .40, and I would ask if you really thought that a 200gr WFNGC at 1350 fps is hands down more effective than the same bullet at 1200? Between the two, I doubt you, me or the animals themselves would notice a difference. Up to a point, pushing faster with a hardcast isn't going to give you better penetration, it can even have the opposite effect and limit penetration. And if that's your goal, you're better off going up in caliber and bullet weight than trying to push it faster to gain penetration.
  18. vandros

    vandros 10mm fan

    This is really interesting, and I've heard this point being made before. It seems very counterintuitive that increasing the speed of the bullet, might actually REDUCE penetration... Could you guys elaborate on this point some and explain how/when/why exactly that might happen?
    #17 vandros, Jan 27, 2013
    Last edited: Jan 27, 2013

  19. If a lead bullet is driven too fast, especially a hardcast, then there is a good chance that if it hits a bone it will shatter when at a lower velocity it would merely punch through.

    Hardcast bullets in a handgun are not as dependent upon velocity to fulfill their mission.
  20. vandros

    vandros 10mm fan

    So, this only affects hardcast bullets? Is faster = more penetration with FMJs?
    #19 vandros, Jan 27, 2013
    Last edited: Jan 27, 2013
  21. RichardB

    Silver Member

    This facts and opinions thrown about in this discussion reminds me of the threads in which some folks want to believe that a beefed up 9mm is the same as the 357.

    Then we go to handloads which may actually only be safely fired in overbuilt Ruger Revolvers. Remember we are talking Glocks, sort of. Hopefully one day Ruger will build a 10mm/ 40 S&W convertible that some of you thrill seekers can fire safely.

    Interesting discussion.:cool::cool:

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