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Vulnerability of the 10mm's Offspring: the 40s&w

Discussion in 'The 10 Ring' started by ModGlock17, Dec 27, 2011.


  1. ModGlock17

    ModGlock17
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    http://greent.com/40Page/ammo/40/180gr.htm

    After reading the above article and its posted data, I've new appreciation for how tolerant and stable the 10mm is.

    Look at the 40s&w pressure data showing how pressure change in just 10mils of bullet set back, using 180gr bullet. Wow! And people are still buying them up without knowing that they are more vulnerable to KBs than other bullet weights.

    Also here is some interest info for those who'd shoot 40s&w in 10mm chambers.
    http://www.thegunzone.com/10v40.html

    I'm posting this for the benefit of new comers to the Big 10.
     

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  2. MightyTygart

    MightyTygart
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    Thanks for the info!
     

  3. Kegs

    Kegs
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    Ol 8 fingers ;)

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    ****EDUCATE YOURSELF BY READING THE FOLLOWING AT YOUR OWN EXPENSE AND RISK!******

    .40 has the stronger case.
    .40 has the stronger case.
    .40 has the stronger case.

    Don't believe everything you read
    !

    but what I wrote above 3 times is 100% fact.

    KBs are a function of firearm design, not case cartridge design. The case will contain the explosion if the barrel will contain the case - all of it beyond the web - not just part of it...

    That author doesn't know what the hell he's talking about.

    His argument is extremely weak and his entire premise is incorrect through inexperience and 100% assumption based on bull5hit. Typical.

    It aggravates me because I know this very subject a whole lot better than other "by the book" folks. It's amazing how much further real world testing gets you than following someone else's directions - but, of course no reward without risk!

    Those who have actually tested the case under real world pressure tests have confirmed that the .40 s&w case will handle FAR greater pressures than the 10mm could.

    I learned this in my extensive research regarding the calibers.

    I can write it all day long and nobody believes me, but it is absolutely true you can load a .40 s&w to .44 magnum velocities (and way more than .44 magnum SAAMI pressure figures) and the .40 case will handle it. The 10mm case will not handle that pressure because the larger primer pocket on the 10mm case is a flaw in the amount of pressure it will really handle.

    It's only short and weak because it's not loaded to its true potential (and production firearms aren't designed to handle its full potential either - and most people don't want to shoot ones that are since there is a ridiculous amount of recoil associated with it).

    Personally, I have only loaded the 40 s&w to a mild power of 200gr. xtps to the mid 1000s fps. I only stopped testing because my conversion barrel is a federal arms barrel and thus not supported all that well.

    It frustrates me that misinformed writers keep spewing garbage, but the readers keep buying it...such is the world I live in.

    As for shooting .40S&W rounds in a 10mm chambered gun, well that is just plain idiotic, but its worth reading for newbs, so its good you posted it.
     
    #3 Kegs, Dec 27, 2011
    Last edited: Dec 27, 2011
  4. _The_Shadow

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    I have to agree about the barrel/chamber is the key to full potential...the semiauto older or modern pushing for smaller package for the cartridge use and reliable feeding with a moving slide is where the issues start. A good example of this is the amount of support being use of the 40S&W conversion barrel from the 10mm pistols due to the longer stroke of the slide with the short ammo. The ammo can feed easily with total case support.

    Given the rounds being used in something like the T/C with a totally closed chamber would make for different cartridge potential altogether...
     
  5. blastfact

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    Hince the folks always looking for 10mm brass with the small primer hole. :)
     
  6. Any Cal.

    Any Cal.
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    I don't really have a dog in the fight, but 2 questions.

    Can the 40 be considered the stronger case if the web is shorter? (Wouldn't it only be the stronger case if it had full case support, at which point it is simply a matter of which primer holds more pressure?)

    In a Glock, why would it be bad to fire .40 in a 10mm, since the case never headspaces on the mouth and the case holds the bullet in position until it is far past the edge of the chamber? (What would be the difference between firing .40s loaded to 1.250 and 10mm loaded to 1.250, with both headspacing on the extractor?)
     
  7. dvrdwn72

    dvrdwn72
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    I don't know, but I was told using titegroup powder in a .40 glock would cause it to blow up? What about in a 10mm? :whistling:
     
  8. SPIN2010

    SPIN2010
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    Searching ...

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    Man! This thread got me so worked up I had to reload about 500 (.40S&W) 180gr rounds to calm down. :supergrin:

    I would have reloaded 10mm but I did not want to change out my 550 small primer bar ... maybe tomorrow. :dunno:
     
    #8 SPIN2010, Dec 27, 2011
    Last edited: Dec 27, 2011
  9. Jitterbug

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    Google for .40 caliber threads and a guy named Clark (sp) he's done some interesting things with a .40, he maintains that with the small primer pocket it's the stronger case.

    Here is one thread...

    http://www.thehighroad.org/showthread.php?t=50011

    Just in case anyone gets any idea's I HIGHLY recommend listening to what Wil Terry had to say about this experiment.
     
    #9 Jitterbug, Dec 28, 2011
    Last edited: Dec 28, 2011
  10. SDGlock23

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    I have heard over the years that the .40 has a stronger case and that's very well possible. I have some small primer pocket 10mm brass too, just never messed with it since I only have less than 100pcs of it.

    With proper chamber support the .40 is capable of quite a bit, as I have messed with some "warm" .40's and they're the real deal. Mass production of .40 cal ammo and older less supportive chambers still out there will lead to problems from time to time.

    Not really sure when that article was written, but 180's I think are still far and away the most popular and there's nothing wrong with using 180's and thinking 180's are a bit too much for the .40 is nonsense. Even 200gr pills can do pretty well from the .40 S&W.
     
  11. Kegs

    Kegs
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    Ol 8 fingers ;)

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    Bingo. Clark Magnuson is the man! An engineer who actually went to the length to test these things until failure.

    Lots of guys will yap and yap and yap based on what they've read written by people who write fully based on assumption, so the assumption gets carried into the shooting community and its all based on b.s. There are at least 3-4 avid glocktalk members that keep pushing the rhetoric around and it turns into a big flame war by the end of the "discussion". Thankfully, most of these folks are not in the 10 ring.

    Very few guys actually test the theories. Clark did. What did he discover? 82% overload on the 10mm is too much. 146% overload on the .40 is okay.

    conclusion:

    NOTE: DO NOT EVEN ATTEMPT IN YOUR GUN!!!!

    14.2 gr. 800x behind a 200gr. speer was too much for a 10mm cartridge.
    15.5 gr. 800x behind a 200gr. speer was okay for a .40 s&w cartridge.

    15.5 gr. 800x behind a 200 gr. speer is a max book load for the .44 magnum.

    NOTE: DO NOT EVEN ATTEMPT IN YOUR GUN!!!!


    Clark's G22 was highly modified, including a double recoil spring somewhere in the neighborhood of 48# resistance IIRC, (recall that the stoutest spring commercially available for full size glocks is in the mid 20#) and the otherwise stock glock g22 barrel on his gun was heliarched around the chamber to ensure 100% case support.


    Who is Wil Terry? Oh yeah, another go by the SAAMI book #s without doing any testing. I.E. not worth paying attention to.
     
    #11 Kegs, Dec 28, 2011
    Last edited: Dec 28, 2011
  12. Kegs

    Kegs
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    Ol 8 fingers ;)

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    double post - ignore.
     
    #12 Kegs, Dec 28, 2011
    Last edited: Dec 28, 2011
  13. Kegs

    Kegs
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    Ol 8 fingers ;)

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    Depends on the remainder of the parameters. Have a look at the cases I cut open and polished and photographed for yourself, but yes .40 S&W is the stronger case due to the larger amount of case web material between the primer pocket hole and the rim (no replacement for displacement):

    [​IMG]

    The case DOES headspace on the mouth of the cartridge in both the 40 and the 10. The 10 is a deeper chamber and thus the .40 case mouth would not meet up with the part of the barrel on which it headspaces to, thus the brass wouldn't be stable in the chamber and when fired, it would put all the pressure to and fro on the rim of the case, which it is not designed for.

    Would it blow up on you? Possibly, but unlikely.
    Would it be accurate? Most definitely not.
    Is it a good idea to do? No.
     
    #13 Kegs, Dec 28, 2011
    Last edited: Dec 28, 2011
  14. rcd567

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    [​IMG]

    Glock grenade or should I say Glock 22, 40 cal.:wow:

    And no, I don't know if that's what actually happened to this poor fella. Just got it and the story off the internet.:dunno::faint:
     
    #14 rcd567, Dec 28, 2011
    Last edited: Dec 28, 2011
  15. _The_Shadow

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    I would suggest some of you take 10mm and 40S& casings (can be older smiled) and using a dremel tool cut them in half length wise to observe the actual internal shape and contours...You maybe in for a supprise to see the differences for different manufactures.

    I see KEGS posted an example while I was typing! Way to go Kegs!

    The manufactures don't really make brass casings to be reloaded, they either make them or have them sub contracted to their specifications. Now consider todays ecconomy and raw material prices...CCI's aluminum casings, Hornady's steel casings these are considered one time use. Both of these are in the buisness of selling reloading products in addition to ammunition line.
     
    #15 _The_Shadow, Dec 28, 2011
    Last edited: Dec 28, 2011
  16. Kegs

    Kegs
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    Ol 8 fingers ;)

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    Yep, and all cases are not created equally either.

    Different manufacturers and different lots could be different build quality.

    Buyer (or loader) beware!
     
  17. Kegs

    Kegs
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    Ol 8 fingers ;)

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    :upeyes: IF you don't know what happened to him, why bother posting the pic? To add to the fear drama?

    Yeah, reloading is dangerous. Duh.

    If you're scared, stand back and pull a string behind a barrier. :tongueout:


     
  18. blk69stang

    blk69stang
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    Yes, it would be bad...

    Because .40 and 10mm DO NOT HEADSPACE ON THE EXTRACTOR. They both HEADSPACE ON THE CASE MOUTH.

    I don't know where you got that idea that they headspace off the extractor, but it's crazy.

    The reason the .40 in a 10mm Glock is a bad idea is illustrated in the link the OP posted; it's possible the firing pin striking the primer of the .40 could push it past the extractor deeper into the 10mm chamber, with the cartridge lighting off with no "breech face" support on the base of the cartridge case. Primer blows out, flame cutting of parts, metals suffer pastic deformation. Click the link in the OP.
     
  19. Any Cal.

    Any Cal.
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    Thanks for posting that! I was going to go cut both cases in half just to see for myself, you saved me some trouble. That .40 pretty much looks beefier all over the head.

    I just measured a G20, and the case can headspace on the case mouth until it is about .970" long it that gun, I haven't measured anything else. So shooting a .40 case means that the round will headspace on the extractor, leaving it .142" short. On a bullet with over .142" in the case, the only issue is that the extractor is absorbing the hit of the firing pin, rather than the case mouth. If the extractor can't take it, it will break and the round will fall into the chamber. If the extractor doesn't break, there is no issue. If the round feeds in front of the extractor, the firing pin cannot hit it, so nothing happens. This would be the case in a Glock 20, I can't speak for anything else.
     
    #19 Any Cal., Dec 28, 2011
    Last edited: Dec 28, 2011
  20. Any Cal.

    Any Cal.
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    I know they are supposed to headspace on the casemouth, but wasn't sure how long they would continue to as you used various lengths of brass. I just measured a G20, and in that gun it looks like they would continue to headspace on the case mouth for all intents and purposes unless you managed to get brass .020" or so short.

    I read that link while ago, and wasn't impressed. If the extractor can hold the case enough to let it fire, it isn't likely to let it slip past. If the case can slip past the extractor, then it isn't likely to provide enough resistance to the firing pin hit to let the round fire. That would be an amazing feat to get an extractor to hold the round enough to let it fire, and then let go of the case and let it fall into the chamber, while not allowing it to return to the breechface on firing.