OK next question re: cartridge length

Discussion in 'Ammo & Reloading' started by DrDenby, May 12, 2016.

  1. DrDenby

    DrDenby New Member

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    I plan to only load 9mm luger, 40s&w, and 45acp

    The problem is that I keep finding conflicting OAL cartridge length. Each powder manufacturer each manual all seem to have a different spec for the same cartridge.

    Where are you all getting your cartridge lengths data?

    What is the proper specs for 9mm jacketed round nose, 40s&w jacketed flat nose, and 45acp jacketed round nose? and what are the +/- tolerances?

    The bullet weight shouldn't matter for OAL right? just the tip?

    Doc
     
  2. SavageGuy

    SavageGuy Active Member

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    The COAL depends on a few things. Mainly the bullet. But also, if you seat a bullet deeper (or vice versa) the pressures with be affected. The more air space inside a case (between the top of the powder and bottom of the bullet) the more pressure. For instance, when loading magnum cartridges such as the .357 or .44 mag, with certain magnum powders (I.e. H110) there isn't supposed to be any airspace in the cartridge. If there is, supposedly the powder with 'flash' and burn too fast which would result in excessive pressure. That is why on the bottle of H110 it says to reduce by only 3% to find a starting load verses the normal 10%.

    Anyway, sorry for the rambling.

    Back to your question.
    SAAMI sets a minimum safe OAL and a max safe OAL. Then the bullet company or powder company sets there own OAL's within SAAMI specs. Just stick to your manual.

    My Lyman 49th sets a OAL of 1.090" for a 115 gr JHP 9mm
    When moving to 147 gr, it moves up to 1.115".

    The MAX safe OAL for the 9mm is 1.169" according to the Lyman.

    Hope this helps!
    ImageUploadedByRuger Forum1463078181.672216.jpg ImageUploadedByRuger Forum1463078194.720609.jpg
     

  3. MagBlackhawk

    MagBlackhawk Patriot

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    You just gotta be sure the bullets are not up against or tooo close to the rifling lands in the barrel and that the OAL is short enough to function in the magazine.
     
  4. DrDenby

    DrDenby New Member

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    Thanks guys.

    This is some good information that went well to explain why I kept getting conflicting recommended lengths.

    Looks like I am gonna need a bullet puller and a lot of experimenting with my guns.

    Doc
     
  5. Tommycourt

    Tommycourt Tommycourt

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    Doc,

    On .45 ACP you can use 1.250-1.255 (safely) for you COAL if you are using 230 Round Nose such as the Berry bullets we talked about. Lymans' book states no longer than 1.273. Not necessary! Just make sure you stay pretty much towards the middle of the powder you are using, not using high or low powder loads. Also on .45ACP you need to run a slight taper crimp on the round. If you can push the round in by pressing it against your bench, then increase your crimp. I would highly recommend getting a case gauge to check your rounds when you are done loading (about $15.00) or if you are in a pinch, pull the barrel off of your pistol and use the barrel as a case gauge. Drop the round in and if it goes it without having to push it, then you are in good shape. Having or loading a "hot" load does NOT mean that you are loading an accurate load. Many times the more accurate loads will be towards the middle of the suggested powder usage or maybe a tenth of a grain or 2 more. DO NOT FIRE ANY ROUNDS UNTIL YOU GAUGE THE BULLET-I CANNOT STRESS THAT ENOUGH!!!! ALWAYS SAFETY FIRST!!!! And again, do not hurry! Learning to reload takes time. I would suggest learning how to load 1 round successfully first before progressing onto a different round. Start out with your 9mm first and then work you way up. This is just my opinion however we have some very experienced reloaders on RT and I believe they will verify what I am suggesting. Good luck and be careful.

    Tommy
     
    Last edited: May 12, 2016
  6. gwpercle

    gwpercle Member

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    The OAL can vary due to different bullet profiles and different chambers. The OAL given is not a must be set at all costs, but rather a a dimension they used in their gun to get the published data. If the round wont chamber in your gun then that particular OAL is not correct for your gun, your OAL may be a little shorter or longer.
    OAL is a starting point, adjust if required and don't be worried if it's not the same as listed.
    Gary