Neck size & tension

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • COTNTOP
    Warrior
    • Mar 2011
    • 168

    Neck size & tension

    When I seat bullets the case shaves copper. What options do I have to remedy this problem? I realize adequate neck tension is very important in semi-auto rifles. THANKS

  • #2
    Are you chamfering the case mouth? What bullet are you using, is it a flat base or boat tail? It is somehat normal to shave jacket off when using a flat base bullet and a chamfer that isn't adequate of even some VLD's will shave unless the camfer angle matches the chamfer angle close enough, that is why the make VLD chamfers http://www.sinclairintl.com/.aspx/pi...hamfering-Tool
    Bob

    Comment

    • COTNTOP
      Warrior
      • Mar 2011
      • 168

      #3
      I am chamfering and using 123 Lapua. Case necks are .257 after FL sized. Worried about proper neck tension for cycling issues. THANKS

      Comment


      • #4
        Also, you can measure the neck tension by comparing a neck before and after bullet seating. The optimum neck tension varries depending upon the powder and bullet you are using but generally .003 is a good amount to shoot for.
        Bob

        Comment


        • #5
          Are you sure, .257 is way small if your talking outside dimenstion. It should be more like .267-.268.
          Bob

          Comment

          • COTNTOP
            Warrior
            • Mar 2011
            • 168

            #6
            THANKS, looks like need to invest in extra equipment.

            Comment

            • bwaites
              Moderator
              • Mar 2011
              • 4445

              #7
              I was about to say, .257? That's tiny, no wonder you are shaving copper!

              Comment

              • COTNTOP
                Warrior
                • Mar 2011
                • 168

                #8
                Inside measurement. Just wondering what is easiest fix?
                Last edited by COTNTOP; 01-09-2012, 04:16 PM.

                Comment


                • #9
                  Are you are resizing the new cases before reloading them? If so, you need a new expander ball.

                  If you're resizng 7.62x39 down, that could feasibly happen. I tried a few cases once out of curiousity and when I measured the ID, it was around .257 IIRC. Not wishing to turn or ream the necks, I abandoned the idea.

                  Hoot

                  Comment

                  • COTNTOP
                    Warrior
                    • Mar 2011
                    • 168

                    #10
                    Yes, resizing new cases.

                    Comment


                    • #11
                      Originally posted by COTNTOP View Post
                      Inside measurement. Just wondering what is easiest fix?
                      Well, that is not as bad but is stil to small, inside should be .261 or there abouts. What kind of dies are you using, and how did you measure the inside diameter?
                      Bob

                      Comment

                      • COTNTOP
                        Warrior
                        • Mar 2011
                        • 168

                        #12
                        Outside neck of loaded rounds are .290, was told that is not excessive. Looking like brass is getting hard and my chamfering might be a little slack, does that sound reasonable. Had an exprienced loader take look today and that was his analysis.

                        Comment


                        • #13
                          Are you using your expander ball?? Some people take it out. If you took it out .... put it back in.

                          Comment


                          • #14
                            I was having the same problem... work harding was the trouble and annealing solved the problem for me

                            Comment


                            • #15
                              How is your brass getting hard if you're resizing new cases? Are they too hard from the factory? What brand of brass?

                              Comment

                              Working...
                              X