OAL for 9mm

Discussion in 'Reloading' started by tapetrowsky, Mar 25, 2010.

  1. tapetrowsky

    tapetrowsky New Member

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    I notice a lot of people give their suggest loads and bullet preferences but no one talks about the overall bullet length. I make 9mm that go from 1.075" to 1.135". It would help to add the AOL to all these great suggested loads.
     
  2. toyrfun

    toyrfun New Member

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    have you been reloading long?

    LOA can vary. yes, the book gives a value, but its for that particular barrel/chamber.

    just an fyi. CZs have really short leadins and some LOAs can be too long.

    getting loading recipes from the web is great, but dont shuck your responsibilites and verify what youre loading.

    i could just as easily give you wrong data, either on purpose or accidently. same for the reloading data manuals. always verify what you reload.

    also, when it comes down to autoloaders, i always do the plunk test with my reloads. i dont taylor them to any one gun since i dont know what i will shoot them in. i make them fit ALL of my guns. i may sacrifice accuracry, but it beats having to keep ammo separate for each gun.
     

  3. tapetrowsky

    tapetrowsky New Member

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    I just started reloading within the past 6 months. I assume the LOA was a shot (pun intended) at my misspelling of the OAL (Over All Length)... I have used 4 or 5 sources for my load recipes, Hornday, Speer, and Lyman to name of few so I believe I have a fundamental idea of how loads run. If I thought the type of people on this forum got their kicks out of giving wrong or in some cases dangerous information.. I wouldn't waste my time and definetly risk my well being on information retrieved form this site. After all your unwanted critquing do you have any worthwhile information to share with me?

    Actually, my CZ compact has an issue with bullet made below 1.100".
    My CZ SP01 has many more rounds through it and it not as finicky. I have shot 1.075" with no problem.
     
  4. wheelgoodtime

    wheelgoodtime New Member

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    tapetrowsky, I try to get OAL values from the bullet manufacturer whenever possible, since nobody tests a given bullet more than those who made it. Some data I have seen does not give OAL (such as bullets made by companies that don't publish loading manuals). In those cases, I will compare a few of those bullets to known bullets I have on hand, and adjust accordingly. For example, I recently bought a large quantity (for me) of FMJ bullets made by Rainier. I couldn't find any data specifically for these bullets, so I compared their length to that of a Hornady FMJ bullet of the same weight, and found them similar enough to use the Hornady data. Frankly, I don't use data from the web, even from here, unless I can find it also published somewhere else. It's just too easy for someone to make an honest mistake- maybe they typed in a 6 instead of a 3, or typed HS-6 instead of HS-7. Always go back to the books, in my opinion, for safety's sake.
     
  5. ajohn151

    ajohn151 New Member

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    I have a similar question to the OP. I am a newb so sorry if this has been covered.
    I am working on my first load of 124g fmj with HS-6 powder and CCi 500 primers. The manual I am using says Min. OAL is 1.090 for this bullet and powder, and max. OAL for the caliber is 1.169. Can I use any length between these two dimensions for this load as long as it functions in my pistol? Do I HAVE to use 1.090 for this load as it is listed with this powder and bullet? I am a bit confused on the whole length issue.
    I completely understand to not go shorter and the dangers associated so that is not what I am wanting. I actually want to go somewhere in the middle such as 1.130 - 1.150. What are the consequences of making the OAL longer than the minimum listed in the load data??
    Thank you for you help,
    Ajohn
     
  6. wheelgoodtime

    wheelgoodtime New Member

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    The maximum OAL of 1.169 is standard SAAMI spec for the 9mm Luger. Anything longer than that, and you may have functioning problems. Your rounds may get hung up on the feed ramp, they might catch on the magazine lips, or they might fail to align with the chamber in time. They could work fine in some guns, but would not be good across the board. The maximum is just an industry standard to which all commercial ammo, and guns, are standardized for reliable function. The minimum length, as you seem to understand already, is for safety reasons- reducing the OAL in a given load can greatly increase pressures due to the decrease in case volume. What I recommend you do, then, is start with the minimum load listed in your load data at whatever exact length you want, and gradually work up your load from there. You will have a larger safety margin if you stay close to the maximum OAL, as the larger case volume will be less sensitive to increases in powder charge, as compared to a shorter OAL. Frankly, I would recommend going as near the maximum OAL as you can, because of the better margin of error offered in that regard. A shorter OAL than standard (maximum) will be more sensitive to variations in powder charge, and therefore more challenging to load consistently. You will likely find that by sticking to (or near) the maximum OAL, that your rounds will be more consistent- key to making accurate ammo.
     
  7. wheelgoodtime

    wheelgoodtime New Member

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    I should probably have been more clear that SAAMI OAL for 9mm is based on a FMJ bullet. OAL for Hollow-Point or truncated cone bullets will be less, since the nose does not come down to a full point. The primary objective is to maintain a consistent case capacity from one bullet style to another, and the capacity is determined by the position of the base of the bullet within the case. That's why I would always try to find some exact data for a particular bullet, if you are not loading FMJs. Shorten up a round too much, and you'll be loading a 9mm powder charge into a .380 sized volume- not a good place to be. There will be some variation in the length of, say, 124 grain FMJ bullets from one manufacturer to another, due to differences in ogive radius, jacket thickness, and base geometry. But, to me, it's the HP's that I want to be especially certain I have good OAL data on, since their geometry can vary widely from one style or brand to another.
     
  8. ajohn151

    ajohn151 New Member

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    Thank you. That is exactly what I thought but was not certain.
     

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