primer pocket cutting

Discussion in 'Reloading' started by Pete L, Apr 3, 2006.

  1. Pete L

    Pete L Well-Known Member

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    is it worth the effort of cutting the primer pockets on lapua brass ?? I used to do all my brass but Iam just preparing a fresh batch for my 243 AI 270 tight neck and Iam wondering is it worth while ?? or would i be better batching the cases in weight,however it is only a hunting rifle
     
  2. EddieHarren

    EddieHarren Well-Known Member

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    Uniforming primer pockets may not make a difference in a hunting rifle but it is a onetime task and surely can't hurt. Remember that, when sorting cases by weight, any neck turning, pocket cutting or trimming to length, will affect weight.
     

  3. col48

    col48 Well-Known Member

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    [ QUOTE ]
    Uniforming primer pockets may not make a difference in a hunting rifle but it is a onetime task and surely can't hurt. Remember that, when sorting cases by weight, any neck turning, pocket cutting or trimming to length, will affect weight.

    [/ QUOTE ]


    so when you sort your cases do you do the prep first or weigh them,????

    its just that i had got in my head that if i prepped them first IE primer pocket,trim to length,flash hole deburr,
    and then weigh them it would give me a better indication of the true weight,this way i am not weighing all the burrs and excess case length.

    when you sort your brass.how many grains do you let them go over or under before you through the case out of that batch.

    as for the primer pockets,i like to do them so i can clean them out after every shot,as i have this tool already,but dose it do anything for accuracy,not as i have noticed,
     
  4. EddieHarren

    EddieHarren Well-Known Member

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    You can weigh them first. Then have to weigh them again after prepping. Unless you can devise a method of removing the exact same amount from each case when prepping.
     
  5. jb1000br

    jb1000br Well-Known Member

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    I have been shooting my latest, a 6BR set up for long range benchrest, without touching anything.

    FH's were LIGHTLY deburred if any burr was present (no chamfer at all, just knock off the burr

    Necks were chamfered

    thats it.

    I will be attempting to test the worthiness of different prep steps soon...

    JB
     
  6. goodgrouper

    goodgrouper Well-Known Member

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    Should prove very interesting and I'll be anxiously awaiting your results! But maybe a less accurate or should I say "less finicky" cartridge would prove more. That darn little 6br shoots great just about any way you load it!
     
  7. col48

    col48 Well-Known Member

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    I personally have never put a chamfer on the flash holes,only lightly deburr
    It is my view (for what it is worth)that no one stage in the prep will do much for CONSISTENCY, But the accumulation of all the processes will--- must aid in consistency.
    I am thinking of weighing my next batch of brass for my 270
    if it takes 2 goes then so be it,

    I know nothing about weighing cases, But i would say if you get out all the burrs, And get them as uniformed as possible,Then weigh them,this might stop you from throwing away brass that might not have made the grade (because it had bigger burrs than the rest)

    How many grains (over or under) do you think is acceptable to sort your cases.
     
  8. HoytemanPA

    HoytemanPA Well-Known Member

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    Col48,
    Don't weigh em twice. Prep em first and use them all.
    Depends on how many cases you have to determine the level of sorting you wish to go to. I use a bell method. If you have for example 50 winchester cases, get em all prepped and start weighing. Set them in full and half grain rows. Example 187 -187.5 one row 187.5-188 another, etc till all the cases are weighed. Probably end up with something like:

    187 - 1
    188 - 1
    189 - 8
    190.5 - 12
    191 - 15
    191.5 - 8
    192 - 4
    192.5 - 1

    In this case, the 35 from 190.5 to 192 would be shot together to fireform and set aside for future good stuff. (Final fine tuning, development of the drop chart, Extreme range woodchucks, hunting, etc.)

    The light ten and heavy five would get used and abused doing 3 shot group variations against each other. Then when you have your load all figured out. Shoot a few 5 shots with the light ones vs the heavy ones on out there a ways to judge for yourself the weighing and it's effects at long ranges.

    That is for setting up a hunting gun. Match gun where you know you will wear out the cases, you may still have 7-8 groups but now they are with a little more consistent brass or at least more of them. The same bell curve sorting goes on but the rows become .1 grain instead of .5 grain and cases more around a hundred or two.

    Careful now. You start doing all this stuff and you can become more and more anal about it. Case in point. I've been developing a load for what I just wanted to be a chuck gun. Brass was sorted to the .5gr level. Had a steady cross wind on a river flat and sent five of one of my prospective recipes down to 475. Shots 1 and two both registered 3149 on my trusty Chrony. They were .635 inches apart shots 3,4, and 5 were 3 inches to the right and 1.5 inches higher and clumped .615 inches apart. 3137,3134,3136. You get to thinking if I would have just sorted to .1, slower speed must have allowed more wind drift. etc, etc and drive yourself crazy. Well heck I'll admit it, I'm going to buy more brass.
     
  9. THOMAST

    THOMAST Well-Known Member

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    Speaking of anal.. the first thing I do is to measure the case necks at 3 points with a tube/ball micrometer to check for consistency.I figure that of you have a case that is obviously thinner in one area of the neck, that discrepancy goes all the way through the case.
    Then I do the weighing thing and yadayada..
     
  10. jb1000br

    jb1000br Well-Known Member

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    GG -- 3 days after that post the rifle didnt let me down at a local g-hog match.

    in fairly bad switchy conditions...maybe 15mph gusts

    5 shot groups at 200,300,500...

    200yds:
    4 in 0.2"
    5th made it about .4 (was actually the first shot that was out)

    300yds: 3 in a cloverleaf
    1 out left in a gust
    driver error dropped a shot low
    STILL under 1" total

    500yds:
    again 3 in a clover leaf
    again one left in a gust
    last shot was about 3/4" above the clooverleaf

    group was 7/8" high by 1.9" wide

    Had the smallest group at 500 and highest score against PPC's and light and heavy 1K guns.

    These BR's are definitely addictive /ubbthreads/images/graemlins/shocked.gif

    I think I'll keep running the way i am for now...I love saving time on brass prep /ubbthreads/images/graemlins/grin.gif

    Taking it to 1K saturday hopefully

    RE: testing Prep Steps in a more finicky case...

    I disagree...with a less precise case/rifle setup, the differences might get lost in the noise...with this thing, the noise level is low, so it "should" be easier to see differences in performance.

    JB
     
  11. jb1000br

    jb1000br Well-Known Member

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    one thing to add -- cases are also weight sorted within a 50rd ammo box...but the weight gradient within the box was destroyed after ultrasonic cleaning.

    weight span is about .5gn over the 50rd box.

    FH's were then LIGHTLY deburred, NO chamfer, NO opening of the FH

    mouths were lightly deburred.

    Groups in the above post came from 1x fired cases sized in a Custom Harrell FL die with 0.0015 shoulder bump and a .267 bushing (NO EXP BALL)

    oddly, the .267 bushing actually gives a nk diam of 0.2682"

    loaded rd = 0.2695"

    Seems i might be doing less prep on my next Comp rifle too(coming next week)

    Im so happy at the thought of NOT having to ream primer pockets!

    JB
     
  12. col48

    col48 Well-Known Member

    Messages:
    261
    Joined:
    Feb 17, 2006
    [ QUOTE ]
    Col48,
    Don't weigh em twice. Prep em first and use them all.
    Depends on how many cases you have to determine the level of sorting you wish to go to. I use a bell method. If you have for example 50 winchester cases, get em all prepped and start weighing. Set them in full and half grain rows. Example 187 -187.5 one row 187.5-188 another, etc till all the cases are weighed. Probably end up with something like:

    187 - 1
    188 - 1
    189 - 8
    190.5 - 12
    191 - 15
    191.5 - 8
    192 - 4
    192.5 - 1

    In this case, the 35 from 190.5 to 192 would be shot together to fireform and set aside for future good stuff. (Final fine tuning, development of the drop chart, Extreme range woodchucks, hunting, etc.)

    The light ten and heavy five would get used and abused doing 3 shot group variations against each other. Then when you have your load all figured out. Shoot a few 5 shots with the light ones vs the heavy ones on out there a ways to judge for yourself the weighing and it's effects at long ranges.

    That is for setting up a hunting gun. Match gun where you know you will wear out the cases, you may still have 7-8 groups but now they are with a little more consistent brass or at least more of them. The same bell curve sorting goes on but the rows become .1 grain instead of .5 grain and cases more around a hundred or two.

    Careful now. You start doing all this stuff and you can become more and more anal about it. Case in point. I've been developing a load for what I just wanted to be a chuck gun. Brass was sorted to the .5gr level. Had a steady cross wind on a river flat and sent five of one of my prospective recipes down to 475. Shots 1 and two both registered 3149 on my trusty Chrony. They were .635 inches apart shots 3,4, and 5 were 3 inches to the right and 1.5 inches higher and clumped .615 inches apart. 3137,3134,3136. You get to thinking if I would have just sorted to .1, slower speed must have allowed more wind drift. etc, etc and drive yourself crazy. Well heck I'll admit it, I'm going to buy more brass.

    [/ QUOTE ]

    thanks for that i will give it a try,theres one thing for sure it can not heart can it.
     
  13. HoytemanPA

    HoytemanPA Well-Known Member

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    Very nice JB,
    Congrats! Is that a 6BR you are working with?
    Shummy
     
  14. jb1000br

    jb1000br Well-Known Member

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    [ QUOTE ]
    Very nice JB,
    Congrats! Is that a 6BR you are working with?
    Shummy

    [/ QUOTE ]

    Shum -- yea, straight br, no-turn .272nk

    JB