C.O.L.

Discussion in 'The Ammo & Reloading Forum' started by Genokumite, Jan 2, 2010.

  1. Genokumite

    Genokumite New Member

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    I am new to reloading. I actually bought all my equipment in November 09. I have yet to reload my first round. Just reading and learning right now. I have three manuals right now Hornady, Lyman and Nosler. My question is why does Nosler only give the maximum C.O.L. I am going to try to load a 150 grain partition spitzer in 30.06. Can I use the specs for the 150 grain (C.O.L.) in the Lyman and or Hornady manuals. Max is 3.34 in Nosler which is all the Nosler manual gives and 3.23 C.O.L in Lyman and Hornady. May be petty but I want to be safe. Thanks for your input in advanced.
  2. Lotsdragon

    Lotsdragon New Member

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    HI and welcome to the forum, one place that can answer a lot of you r questions is the IMR website.Looking at my lee dies I see that 3.340 inchs is the max. There aint no petty questions when it comes to reloading, take your time do it right or you will regret it immensly. Have fun and be safe!
  3. Gearheadpyro

    Gearheadpyro New Member

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    It is likely due to the Nosler bullet being just a little bit longer than the others. Use the information from the bullet manufacturer you are using, if you have that manual. Otherwise I would go with the 3.23" C.O.L.

    The factory C.O.L. which is listed in the manual is a good starting point. Each gun will have a different maximum C.O.L. though. You will need to tune your ammunitions C.O.L. to your gun in order to get the best group sizes. That's one of the many benefits to reloading.

    I wrote an article on load development that will help you out with this (still working on a few of the linked pages). (http://www.rifles-shooting-reloading.com/load-development.html)
  4. steve4102

    steve4102 Former Guest

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    The Max COL listed in manuals has very little to do with your particular firearm. Each firearm will have it's own max COL. The Max COL listed in the manuals is for ammo manufacturers so as every round sold will fit every firearm made. The handloader is free to adjust the COL to fit his or her specific needs.

    From Accurate Powders..
    SPECIAL NOTE ON CARTRIDGE OVERALL LENGTH “COL”
    It is important to note that the SAAMI “COL” values are for the firearms and ammunition manufacturers industry and must
    be seen as a guideline only.
    The individual reloader is free to adjust this dimension to suit their particular firearm-component-weapon combination.
    This parameter is determined by various dimensions such as 1) magazine length (space), 2) freebore-lead dimensions of
    the barrel, 3) ogive or profile of the projectile and 4) position of cannelure or crimp groove.


    From Hornady #7

    [​IMG]
  5. rocklinskier

    rocklinskier New Member

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    On this subject, I have a question as well.

    If you use the same powder load, but adjust the COL, what is the effect on the pressure?

    For instance, If one bullet is seated at 3.20, and another at 3.35, both with the same powder load, will the deeper of the two increase pressure and or velocity to a notable degree?
  6. steve4102

    steve4102 Former Guest

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    In bottleneck rifle cartridges there is no real answer to this question. It has long been thought that the deeper the bullet is seated the higher the pressure,(less case volume). Barnes among others have tested this theory in pressure testing equipment and found just the opposite in some rifles. They also found a increase in pressure in some rifles. So, the answer is "Maybe".

    Will you notice a increase or decrease in pressure from 3.20 to 3.35, probably not, as long as these loads are not crowding the lands and there is sufficient bullet jump. Crowding the lands will increase pressure for sure. If the load is near or at Max, wouldn't hurt to drop the charge down a bit and work back up when changing OAL.
    Last edited: Jan 3, 2010
  7. Genokumite

    Genokumite New Member

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    Wow! Thank you everyone for all the information. I really appreciate you time and information given. Now with deer season over I will begin working up an accurate coyote round for this summer and a big game round for next hunting season and get proficient in shooting both.

    Thanks again!!!!!