Neck tension trouble, 6.5x284

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by PAMONTY, Aug 31, 2003.

  1. PAMONTY

    PAMONTY Member

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    Aug 10, 2003
    I seem to have a tight spot in the neck of my brass, Its down near the shoulder and bottom of the neck. I can take a fired brass and start a bullet down the neck, the bullet will stop when it reaches this junction.(NECK/SHOULDER) Seems like a donut at the bottom of the neck. I have to think this is not good for ES. Fired 10 rounds this morning ES was 87 fps.
    I can feel MORE resistants when seating bullets, They started down with even pressure then increase as they break thru the neck into the shoulder area.

    I reamed the inside of the neck twice now. Tonight I reamed for the second time, bullet droped staight thru into the case with no resistants. Resized the brass and the tight spot returned.
    Now I measured the shoulder to base before resizing and after. Only moved the shoulder back .002, If I don't bump the shoulder I have a stiff bolt- if I do I have the neck tension problem.

    Has anyone dealt with this before?

    Equipment list:
    Norma 6.5x284 brass
    Redding fl bushing die.
    Redding shellholders in .002 increments.

    Thanks
     
  2. Darryl Cassel

    Darryl Cassel Well-Known Member

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    Penn

    Don't bump the shoulders so much, if any. Your pushing the juncture of the shoulder into the neck area creating the tightness at the base of the neck.

    It's better to have some snugness against the bolt anyway. The cartridge is fitting the chamber better.

    Try full length resizing but, not bumping at all and set the die so you only resize the neck 1/2 way down.

    If you use a neck bushing, with a full length die, you can accomplish the exact neck tension your after as long as you know what your neck diameter is in the chamber.

    See what your extreme spread is without any shoulder bumping.

    I like very little neck tension.

    Later
    DC
     

  3. PAMONTY

    PAMONTY Member

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    Thanks Darryl
    Bumping that shoulder is tricky business. I bumped that shoulder back .002 is all and it cuased all that neck tension trouble. I'm started to think there's more resizing done to the walls of the case than the shoulder. I have heard so much about shoulder bump in my short reloading career, it seems logical to think we need to push it back.
    I have achieved the tension I want--about .001 or less press. Now all I have to do is wait the rain out. I have 11 rounds loaded I want to run thru the crony. Hope to drop that ES of 87 down quite a bit.
    There's a fine line between good headspace and a sticky bolt.
    I will report back the results of those rounds as soon the rain stops.
     
  4. DANTEC

    DANTEC Well-Known Member

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    to try to avoid your neck junction , perhaps try to use a full sizer set just 0.002 under your chamber headspace ( to allow easy chambering
    BUT
    with a radius junction between neck and shoulder slighty bigger than the chamber radius big problem with regular die ( not custom design for BR ) they are made with two reamers one for the body and the shoulder , one for the neck so you get a sharp angle between neck and shoulder and you put stress in brass material a lot with a radius you sucess to bump your shoulderand size neck .

    you can use a full sizer as it with bushing to set the neck sizing you want

    on short neck case best is to resize up to 90% of the neck to get a longer aera long enought to avoid of center bullet and use a cocentric chamfer close the boatail angle to doesn t use the bullet as neck sizer mandrel .

    good shooting

    DAN TEC
     
  5. jb1000br

    jb1000br Well-Known Member

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    K&M i beleive makes the most popular tool for removing donuts--im sure someone on here has ken's Phone#--i dont right now.

    you get donuts from neckturning--happens all the time. the fat part just on to the shoulder flows forewad into the neck causing the tight spot--yes it is a killer on SD.
    --should be able to find him on an internet search. ken markle/K&M products (i think)

    JB
     
  6. DANTEC

    DANTEC Well-Known Member

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  7. PAMONTY

    PAMONTY Member

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    Getting closer. Finally got to shoot those 11 rounds. E.S. was 56, a drop of 31 fps from the original 87 E.S.

    I reamed the doughnut out with a forester neck reamer. This gave me a seating press of about .001. Also I reamed the flash hole, measured and weighed each bullet. Tried to go the extra mile.

    I was hoping to keep ES under 20 butttt. One thing I might have over looked was how clean the bore was. I plan to clean it, and then clean it somemore and try the test again.

    By the way the range I was shooting was 300 yards, Shot two groups. 6 shots measured 1.375" and 5 shots 1.105"

    If anyones interested I will post results of second test, I know its got my interest up.
     
  8. FatBoy...

    FatBoy... Well-Known Member

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    jb1000br,

    Getting the doughnuts from neck turning is the common explination, but I get them on one of my rifles, and I do not neck turn. I think it has something to do with the chamber I'm using, as there are at least 5 others shooters out there getting doughnuts, that don't neck turn, same chamber reamer used.

    Funny thing is, I reamed the necks on 10 and left 10 with doughnuts. My scores at 1000 were no different with the doughnuts. I dropped 1 point with the reamed, and 1 point with the doughnuts. Actually, my X count was 1 higher with the doughnut.

    Maybe I'm just lucky.....

    Chris...
     
  9. hhmag

    hhmag New Member

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    Sep 2, 2003
    I had a similar problem with both a 6.5x.284 and a .30-06 AI. I did not neck turn at all, but some old guru asked me how closely my dies matcked my chamber. I ended up re-reaming the 6.5x.284 with a Norma reamer and ended the problem. I also had very little sizing to do afterwards. I set up a FL die (redding) to neck size, and only had to size about 1/2 of the neck and never bumped the shoulder. I was only loading to about 2850, but it was tighter than I could shoot. [​IMG]

    The .30-06AI was a different story, I ended up oversizing the flash hole a bit and switched to non magnum primers. It seemed to me the brass was "flowing" forward faster than normal trimming and sizing could handle. I lost about 150 fps, but es went down to about 30 and the best groups were sub 6" at 750meters (the longest range I had access to at the time).