Page 1 of 3 123 LastLast
Results 1 to 15 of 40

Thread: Necking up to a 30BR. Run out!!

  1. #1
    Join Date
    Feb 2007
    Location
    Mattoon
    Posts
    3,145

    Necking up to a 30BR. Run out!!

    Whats the proper way to neck up a 6BR case to 30cal without causing a bunch of run out to the case? I am having some 30br brass made and i have noticed that the necked up cases can have as much as .020 run out after necking them up. There has to be a way to minimize this run out. I am also worried about how accurate the turned necks will be since there is so much run out in these cases. The necks all measure pretty close as far as neck thickness goes however. I am having trouble getting these cases 100% straight even after two firings. I am using a crush fit while fire forming but i still See up to .004 run out. I am going to start turning my own brass here this winter so i am just looking for tips and ideas, thus the reason for this post. Is there a die or something a guy can use to help support the case while necking it up to minimize the run out effects of the expander mandrel? It seems to me if there isn't there should be! Also how can i get these cases straight? I dont know what else to try. I lube the cases, i crush fit the brass on head space, i jam the bullets, and i use a stout load. Some of the brass is around .001 to .002 but a few pieces are still around .004 to .005 after two firings.
    I had this same issue with the last batch of 30BR brass i had made, so it seems to be a common issue with this stuff. What do i need to know? thanks Lee

  2. #2
    Join Date
    Feb 2003
    Posts
    67
    Have you tried the cream-of-wheat method yet? Using a small charge of pistol powder, around 13.5g of W231, in a 6br case with a wee bit of klennex to hold the powder in the case and fired in a 30BR chamber. OK, I don't use COW, I use klennex
    Last edited by Keith Skjerdal; 12-07-2010 at 08:50 AM.

  3. #3
    Join Date
    Feb 2003
    Location
    Tuff, TX
    Posts
    776
    Lee, go back and search around until you find Jackie Schmidt's posts about making 30BR cases for the long neck 30BR. Basically, you make a fire forming barrel with a .332 neck. You do this by boring the neck area out with a chucking reamer. Then you fire form the cases via the cream of wheat method. What comes out is a perfectly straight case about 1.550 long. We use a reamer that cuts a neck long enough that we do not have to trim this neck back to 1.525 but you probably would have to trim your cases.

    joe

  4. #4
    Join Date
    Feb 2003
    Location
    Frederick Md.
    Posts
    2,811
    Quote Originally Posted by skeetlee View Post
    Whats the proper way to neck up a 6BR case to 30cal without causing a bunch of run out to the case? I am having some 30br brass made and i have noticed that the necked up cases can have as much as .020 run out after necking them up.
    Well as long as you have it made for you you are stuck with the way the person makes it. So the first thing you need to do if the runout worries you is start making your own brass. I recommend blowing it out with pistol powder as your first step. Like Joe Duke said above find Jackie's old post on the subject.

    Dick

  5. #5
    Join Date
    Nov 2004
    Location
    Central KY.
    Posts
    34
    Runout after 2 firings?
    Are these cases from the new blue box by any chance?
    Do you have access to a few cases from the old paper box?
    Can you have some of your new cases annealed?

    I think at some point some of the Lapua 6BR brass began to not be annealed properly. Seems about the same time as the new blue box began. We found out last winter that some (20%+) cases of one batch had excessive runout after several firings. They were culled but we haven't checked our latest batches. I plan on annealing my next batch before I do anything else to them.

    Anyone else having issues with runout on fired cases? Has anyone checked?
    TonyinKY

  6. #6
    Join Date
    Jan 2004
    Location
    Viva Las Vegas
    Posts
    342
    Quote Originally Posted by TonyinKY View Post
    Runout after 2 firings?
    Are these cases from the new blue box by any chance?
    Do you have access to a few cases from the old paper box?
    Can you have some of your new cases annealed?

    I think at some point some of the Lapua 6BR brass began to not be annealed properly. Seems about the same time as the new blue box began. We found out last winter that some (20%+) cases of one batch had excessive runout after several firings. They were culled but we haven't checked our latest batches. I plan on annealing my next batch before I do anything else to them.

    Anyone else having issues with runout on fired cases? Has anyone checked?
    TonyinKY
    Here we go again. Only the cardboard box brass is any good. Whats next?

  7. #7
    Join Date
    Oct 2005
    Location
    Tomball,Texas
    Posts
    962

    Exclamation I think this is the post you are referring to.

    Quote Originally Posted by Joe Duke View Post
    Lee, go back and search around until you find Jackie Schmidt's posts about making 30BR cases for the long neck 30BR. Basically, you make a fire forming barrel with a .332 neck. You do this by boring the neck area out with a chucking reamer. Then you fire form the cases via the cream of wheat method. What comes out is a perfectly straight case about 1.550 long. We use a reamer that cuts a neck long enough that we do not have to trim this neck back to 1.525 but you probably would have to trim your cases.

    joe
    http://benchrest.com/showthread.php?...=30br+fireform

  8. #8
    Join Date
    Jan 2004
    Location
    Viva Las Vegas
    Posts
    342
    Thanks for the pic. You made my day!

  9. #9
    Join Date
    Feb 2007
    Location
    Mattoon
    Posts
    3,145
    Thanks fellas thats some good reading. I am gearing up to turn my own brass this winter. Its time for me to learn anyway. The brass i get turned for me always seems to shoot just fine, but me being me, I'm just kinda picky and i like my brass to be straight. I have been reading an talking with some good folks about the proper procedures, and i think i will be just fine. It really doesn't seem all that hard. I have bucket fulls of 223 range brass from the city range so i have plenty to practice on, plus it will give me something to do this long winter! Now i just need to buy a few more tools and find a shot out 6br barrel. lee
    Last edited by skeetlee; 12-07-2010 at 07:01 PM.

  10. #10
    Join Date
    Feb 2003
    Location
    Frederick Md.
    Posts
    2,811
    Quote Originally Posted by goodgrouper View Post
    They say a picture is worth a thousand words.
    I gotta say I loved that .

    Dick

  11. #11
    Join Date
    Dec 2003
    Location
    washington.........STATE that is.
    Posts
    11,033
    My opinion......

    You will ALWAYS end up with more runout when using a mandrel.

    You will ALWAYS get less runout using COW

    You will ALWAYS have people who don't know any better insisting it's all irrelevant.

    (I bay'n making cases for a long time. And arguing with folks who feel their way is "just as good".......... all the while whining about crooked caseheads/annealing problems/cracks/inconsistent seating force/tuning problems/scope problems/rectal fissures etc etc........)

    Ken Howell told me this a long time ago.

    He's a fart smeller Ol' Kenny.....

    al

  12. #12
    Join Date
    Oct 2005
    Location
    Tomball,Texas
    Posts
    962

    Exclamation Tony Boyer On Bullet Concentricity

    In regards to seated bullet concentricity TB says,

    "When shooting with the bullet into the lands, the lands themselves staighten the the bullet without forcing over travel."

    "I let the dies and the lands take care of concenticity."

    Source;

    The Book Of Rifle Accuracy

    Page 258

  13. #13
    Join Date
    Dec 2003
    Location
    washington.........STATE that is.
    Posts
    11,033
    Quote Originally Posted by goodgrouper View Post
    So far, zippo, zero, notta bit of evidence has been found!

    .
    Information of which you're not aware does not constitute "zippo, zero, notta bit of evidence".......

    except in your own mind.

    al

  14. #14
    Join Date
    Feb 2003
    Location
    Lower Dakota Territory
    Posts
    1,940
    Lee: I've used every method out there to make 30BR cases...and some that haven't been discussed. The method I favor is still the expand-up method over a mandrel, for several reasons. No need to go into the reasons, as that'll spin off into a whole 'nother direction. Case necks expanded over a mandrel will have excessive runout. But it's pretty simple to correct.

    I use a neck bushing that's .001 under what the average case neck o.d. is after it's been expanded, then simply run the case back into the f.l. die with that bushing. That straightens the neck out relative to the case body and you can neck turn at that point. If you need to expand up a skosh for a better fit on the turning mandrel, you can now do so w/o inducing a lot of runout..since you're only expanding the neck a very small amount.

    On the 30BR's, there is a 'lump' that forms at the bottom of the necks after expanding up from 6mm (that used to be the shoulder) that's about .060-.065 in height. I use a spacer setup to allow the bushing to have that much extra room so it doesn't jam into the 'lump'. You can do that by either raising the bushing in the die or spacing the top of the die back to let the bushing float upward. Doesn't take much to lash up something that will work.

    Neck bushing size used is .335, but that may be different with the new blue boxed cases, as they have slightly thinner case necks.

    Good shootin'. -Al

  15. #15
    Join Date
    Feb 2003
    Location
    Fresno
    Posts
    5,545
    Good points....Do your own research. Don't be intimidated if your results contradict what you have read or heard. Go with what works. If it isn't broke, don't fix it. Nothing is a substitute for practice.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •