bullet seating depth HOW TO ?

Discussion in 'Reloading' started by haywire05, Jul 18, 2009.

  1. haywire05

    haywire05 Well-Known Member

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    Finally got my first long range gun . Guy I bought it from said seat off the lands at .015 thousand. He was shooting 2.9"@600yds with this gun and has the load development with it . Just need to make shure I load properly . Have loaded hunting rifles before but nothiing like a long range shooter.

    Question on bullet seating depth . Have had numerous people tell me how to do it .
    But does this work pushed in a bullet in a new case by hand and fed it in to the chamber seating it with the bolt and then Proceeded crank my redding die down onto the bullet till it just touches . locked it in and then backed off the micrometer 15 thousand . Is this right if not please tell me . I really want to get shooting this gun and see what i can do . Cheers
     
  2. AJ Peacock

    AJ Peacock Well-Known Member

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    You said you would 'back off 15 thousandths', that would make it into the lands. The way I understood your question was that you wanted to be OFF the lands .015", so you'd want to go .015" deeper.

    You likely have the right idea, just do your measurement 6-8 times to make sure you know exactly where your lands are.

    AJ
     

  3. woods

    woods Well-Known Member

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    Like AJ said, if you want to be off the lands then you need to thread your seater in further to push the bullet deeper in the case. You are also going to push the bullet a significant distance into the lands if you are seating the bullet in a new case and chambering it to let the bolt push the bullet further in. A new case usually has somewhere around .003" bullet grip which holds the bullet well and the bullet will resist movement in the neck and be pushed into the lands. Also the lands will grab hold of the bullet and when you extract the case there is the very real possibility of the bullet moving back out of the case neck some distance before it releases from the lands.

    Easiest way to measure to the lands is to get the Hornady OAL tool and learn to use it. Other ways include

    1. Cutting a slot in the neck to make the bullet movement easier as you chamber it
    2. Blackening the bullet to gauge when you are no longer hitting the lands and if the bullet is moving in the case neck
    3. Cleaning rod or dowel down the muzzle to the bolt face and then to the tip of a lightly seated bullet, marking the rod and measuring between the 2

    Probably others I have left out. Get the Hornady and you can get lots of help here and elsewhere to learn to use it because many use it.
     
  4. haywire05

    haywire05 Well-Known Member

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    I meant screw it in another 15 thousaands . Hope this is right .
     
  5. woods

    woods Well-Known Member

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    If you have a fired and unsized case then you can get better results by very slightly oblongating the case mouth so that it lightly holds the bullet, then using the bolt to push it into the case. Repeat several times and mark the bullet with a magic marker to see if the lands are pulling the bullet back out. Use the magic marker also to blacken the bullet where the lands hit and see if it is still hitting after you have decided on a seating depth.
     
  6. haywire05

    haywire05 Well-Known Member

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    Woods thanks that is exactly what iam doing right now . Cant wait to start shooting ! Iam like a kid in a candy store right now .
     
  7. MontanaRifleman

    MontanaRifleman Well-Known Member

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    Here's the way I did it with my Sendero which was not making any lands marks on the bullet after blackening it with a sharpie.

    Neck size a case... new is best so it fits easily in to the chamber.

    Seat a bullet into the case and use a kinetic bullet puller to pop it out.

    Repeat this process until the neck is streched enough that you can seat the bullet by hand and move it up and down the neck by hand, but still have some slight tension. I had to repeat about 20 times. :rolleyes:

    Then, seat the bullet a little long by hand and measure the COAL

    Slowly and carefully, insert the cartridge and chamber with your bolt.

    Slowly and carefully open the bolt and remove the cartridge keeping a finger on the case so it doesn't flip out.

    Remove and measure the COAL.

    Pull the bullet out of the neck slightly and repeat the chamber and remove/measure process several times to ensure you are getting a consistant reading.

    Neck size another case and seat the bullet a little long and measure. If you have a micrometer seater the rest is easy. If not, keep seating the seater deeper until you get the correct COAL, then lock it in.

    I did this with three different type of bullets and it worked like a champ.

    A little time consuming, but IMO, very accurte.

    Also, if you dont have a micrometer seater (get one) make a seated gauge from an uncharged, unprimed case and bullet that you can use to turn the die down on until it stops on the bullet for future seating... especially if you are working with more than one bullet.

    -MR
     
    Last edited: Jul 18, 2009