OAL Confussion

Discussion in 'The Ammo & Reloading Forum' started by Technohead, Feb 9, 2010.

  1. Technohead

    Technohead New Member

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    I have been reloading for years, however I am self thougt. The problem I am having is I have determied the maximum overal length of case for my TC encore 22-250 and have set my Rock Chucker press using RCBS standard dies to 0.003 shorter than max using the ogove to base of case measurement.

    When I seat many to the bullets using this setting the length comes out within 1 or 2 thousants but several will also come out as much as 0.005 too long and one even came out 0.008 too long. I have put them back in the prees and made sure I bottomed the stroke out but they remain too long.

    What gives, I can't figure it out. This seems to happen at random but obliously I can't accept this inconsistancy.:confused:
  2. Jim K

    Jim K New Member

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    Re: AOL Confussion

    Well .005 really isn't much in terms of OAL (measure any box of factory ammo), but the things that come to mind are inconsistency in the bullet ogive, dirt in the bullet seater, or play in the press. It is also possible for a lead soft nose to be compressed that much. (Just FWIW, a sheet of printer paper is .004".) If you are trying to eliminate variables, measure the OAL of each round and set aside any that are too long or too short.

    You might dispute this suggestion but, to be honest, I wouldn't worry about it.

    Jim
  3. Lee C.

    Lee C. New Member

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    Re: AOL Confussion

    Technohead, You can do a few things, measure your bullets and sort them by lenght. then load them that way and reset your setting die for the longer bullets. What I did was to take the setting stem out of the die and drill it out alittle then polish it with flitz. That help me with the bullets that where a little longer than the rest. Hope that helps ya some,
  4. Technohead

    Technohead New Member

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    Re: AOL Confussion

    Thanks Lee I think that you have something there. I'll try it. I guess because I was useing ogrove measurements I overlooked the fact that my dies might be contacting the bullets at a point closer to the pointy end.
  5. dteed4094

    dteed4094 New Member

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    Re: AOL Confussion

    Better a little too short than long. You have a tendancy to burn the throat out of the chamber with too long of ammo especially in a 22/250. Are you checking brass length. How many times has the Brass been fired?
  6. Innovative

    Innovative New Member

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    Re: AOL Confussion

    Here's a good article on OAL. This page shows the best way to measure OAL for the most accurate handloads, and it goes into more detail than most of the info you read in reloading manuals. Hope it helps.

    How to Measure your OAL

    - Innovative
  7. Jim K

    Jim K New Member

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    Excellent article. But what you need to measure is where the ogive equals the bore (or land, not the groove) diameter. For a .308, that would be where the ogive measures .300". That is the point where the ogive will contact the lands (the curb, to use his automobile analogy). That is also the point that will give the best protection against barrel erosion.

    Jim
    Last edited: Feb 15, 2010
  8. Innovative

    Innovative New Member

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    Jim K .......
    You're right that the larger diameter (that contacts the rifling) is the most significant. However, the angle there is so shallow that you'll never get a repeatable measurement. It's best to measure halfway between there and where the seating stem contacts the bullet.

    - Innovative
  9. cltbruce

    cltbruce New Member

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    How i do it is I shoot military surplus rifles that have deep chamber throats to find tru depth i make up a dummy load no powder no primer just projectile and make the dummy as long as you can O A L then i paint the end with asharpy pen then I crfuly put it in the gun and see if the bolt closes and then look on the end of bullet to see if its scuffed if it is i paint it again after setting bullet a little deeper in to brass when i get no scuff i quit and then use that round to set my seating die to when i reload it takes awhile but it works for me I hope this helps
  10. mikld

    mikld Active Member

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    Another thought, the bullets are mass produced and perhaps there is enough variation of the ogive to give varying c.o.l. lengths. In addition to the other variences, you might get "stacking" tolerances...

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