Anyone heard this?

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  • Anyone heard this?

    I was at a gun show this weekend and stuck up a conversation with a guy there about the Grendel. I mentioned that I have had some trouble recently with some unformed 7.62 cases. He said that in the process of going from 7.62 to Grendel, some cases can come out significantly different lengths. I have noticed this. In some instances up to .1" difference. He said when setting up the seating die, if you measure off a short case, then shove a longer case in there, it can distort the shoulder dimensions. Makes sense! Anyone heard of this?

  • #2
    You're talking about 7.62x39 aka 7.62 short/Russian, correct?

    Yes, cases can do deviant things when forced into different sizes.

    Another reason to buy Grendel brass. I have piles and piles of 7.62x39 Finnish military brass for the Rk62 and Rk95 rifles, which is made by Sako or Lapua, and it is beautiful brass. I won't mess with it since it has Berdan primers, although they can be blown out with pneumatic or hydraulic pressure.

    I just buy Lapua brass and don't worry about it, as I'm not shooting high volume in the Grendel anyway.

    LRRPF52

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    • #3
      No, I use Grendel brass, it is cheap enough.

      By the time you get done forming 7.62x39 into Grendel brass you have spent more than the Grendel brass costs.

      Wolf brass can be had cheap, Hornady is cheap and very good, why settle for performance that it is less than adequate?

      Comment

      • LR1955
        Super Moderator
        • Mar 2011
        • 3355

        #4
        Originally posted by Oobray View Post
        I was at a gun show this weekend and stuck up a conversation with a guy there about the Grendel. I mentioned that I have had some trouble recently with some unformed 7.62 cases. He said that in the process of going from 7.62 to Grendel, some cases can come out significantly different lengths. I have noticed this. In some instances up to .1" difference. He said when setting up the seating die, if you measure off a short case, then shove a longer case in there, it can distort the shoulder dimensions. Makes sense! Anyone heard of this?
        OOB:

        You ought to see some 22-250 brass that was shoved into a 6XC sizing die for fireforming into 6XC. Pretty ugly with the shoulder bulged way more than I have seen any 7.62 X 39 bulged to form Grendel. One thing about it though is that the shoulders of all the brass are set back the same amount no matter how long the brass is.

        I will say that .1" is pretty much -- which is why the reloading companies make trimming tools.

        Today unless you really want inexpensive brass to blast and probably not care if it is left on the ground, buying Hornady Grendel brass is a better option. The Wolf brass from the MPT ammo is also a good option.

        LR1955

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        • #5
          A year or two ago, I thought that buying the Winchester 7.62x39 cases at $39/100 would save me money. After I figured in the cost of primers, powder, bullets to fireform them, and the usual cases lost to crushing during the forming process (I always seemed to loose one or two), the cost was about the same as buying Grendel brass to start with.

          The other thing that I had to figure in was that the large primers on the 7.62x39 cases meant that the primer pockets simply didn't last as long as the Lapua Grendel brass. Usually, the primer pockets on the 7.62x39 cases would begin to get too loose to use around 3 firings. The Lapua Grendel brass lasts a really long time...even longer if I remember to anneal it.

          Comment

          • pinzgauer
            Warrior
            • Mar 2011
            • 440

            #6
            While I agree it no longer makes sense to buy 7.62x39 to try to save money, I've had excellent results with IMI 7.62x39. Sizes and fireforms with no problems, I'm getting 7-8 firings out of them before I retire them due to split necks or loose primer pockets.

            Reduced capacity is the main disadvantage. It mainly impacts bullet/powder selection, as the velocity loss is not directly proportional. IE: 5% less case capacity does not equal 5% less velocity. (LR1995 was the first to document this on the old forum) You can definitely find combinations that result in severe compression which would work in a normal grendel case. 2520 & 123AMAX work fine, as do 120g SMK's.

            Likewise, my fireform loads tend to be quite accurate, and for 50 yard usage are largely indistinguishable from full power loads. And I have one fireform load (2230 and 100g bullets) that shoots to same POI as my full power loads.

            Overall length has not been an issue, and while it does vary some it's normally shorter rather than longer.

            I do think good lube and reloading gear helps with the forming process. I use Hornady spray lube and forster co-ax press with forster dies. Never lost a case in forming 7.62x39 except early on when my son hit one too hard that had not been lubed right.

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            • #7
              Yeah I was looking around at Grendel brass and it seems to be pretty plentiful and cheap now. I have been overseas for a while and the rounds I shot were from atleast a year ago. Before I left gredel brass was only from lapua or AA and incredibly rare and expensive. Hints, why I was using the 7.62 brass. I have around 50 formed cases now so I'll use those and go ahead and order some hornady brass. It's available on midway right now.

              Thanks guys

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              • #8
                Originally posted by pinzgauer View Post
                While I agree it no longer makes sense to buy 7.62x39 to try to save money, I've had excellent results with IMI 7.62x39. Sizes and fireforms with no problems, I'm getting 7-8 firings out of them before I retire them due to split necks or loose primer pockets.

                Reduced capacity is the main disadvantage. It mainly impacts bullet/powder selection, as the velocity loss is not directly proportional. IE: 5% less case capacity does not equal 5% less velocity. (LR1995 was the first to document this on the old forum) You can definitely find combinations that result in severe compression which would work in a normal grendel case. 2520 & 123AMAX work fine, as do 120g SMK's.

                Likewise, my fireform loads tend to be quite accurate, and for 50 yard usage are largely indistinguishable from full power loads. And I have one fireform load (2230 and 100g bullets) that shoots to same POI as my full power loads.

                Overall length has not been an issue, and while it does vary some it's normally shorter rather than longer.

                I do think good lube and reloading gear helps with the forming process. I use Hornady spray lube and forster co-ax press with forster dies. Never lost a case in forming 7.62x39 except early on when my son hit one too hard that had not been lubed right.

                That's pretty much my experience. I am using a Redding Ultramag press and dies. Early on when Grendel brass was almost unobtainable, I purchased 2000 rounds of IMI 7.62x39 brass, and started resizing using imperial die sizing wax. That got old in a hurry so I sprayed a lot with some 3M teflon/silicon spray lube and went to town. It worked fine and was easy to clean up. I may have lost half a dozen cases in the process. The all fit fine in, cannot remember maker at the moment, cartridge gauge I got from Alexander Arms , and function good in my rifles.

                Comment


                • #9
                  The Sheridan case gauge

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                  • #10
                    I didn't see any problems like that. I don't own nor have I shot any Grendel brass/ammo in either of my rifles. I bought 1K of the IMI 7.62x39 cases back when they were still around. I also had a few thousand Winchester 7.62x39 cases and fire-formed them all for the 6.5. The ONLY problem I had at 1st was setting the shoulder back far enough on the intial re-size. Once I found where that point should be, I was good to go. I fire-formed over 2500 cases w/o any other problems.

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                    • #11
                      What brass is out there beside AA, Lapua and Hornaday?

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                      • bwaites
                        Moderator
                        • Mar 2011
                        • 4445

                        #12
                        Wolf.

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                        • #13
                          Cool, who has it?(not that I really need more now) I was looking at Midway and they only had the 3 I mentioned..
                          Thanks
                          Greg

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                          • bwaites
                            Moderator
                            • Mar 2011
                            • 4445

                            #14
                            Wolf doesnt sell components, so you have to shoot new and recover it, or buy from someone who doesn't reload.

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