Fireforming 7.62x39 brass

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • LR1955
    Super Moderator
    • Mar 2011
    • 3355

    #16
    Originally posted by ironhorse18 View Post
    Hello Folks, I am new to the 6.5 Grendel, I am in the process of putting one together now. Reference converting 7.62 X 39 brass to 6.5 Grendel, what's best process to utilize: Hydro Forming or Re-size with FLR size die. I have never tried the Hydro method, but I'm willing to try. Also, looks like all methods require fire forming. I have a small pile of Lapua "S-K" brass I could use. I ordered 50 Hornady to begin with, that's about a $buck a piece. Maybe a brass catcher is in order...............

    At this time: on AR Platforms, .223 Wylde, 300 AAC, 25 WSSM, & 6mm X 45.
    Resize using a good sizing die, use a minimum load with a light bullet, shoot.

    You will have to size the neck down in order to hydroform so just avoid having to plug primer pockets and get water sprayed all over the place and size it down, load it and shoot it.

    Hydroforming forms the body of the brass and some say it alleviates that first shot blowing out the brass. Others have said hydroforming doesn't completely blow the brass out so they have to shoot it anyway.

    LR55

    Comment

    • ironhorse18
      Unwashed
      • Sep 2015
      • 21

      #17
      Hello again to all. I just received my order of Hornady 6.5 Grendel brass and a set of RBCS .264 LBC dies. I had been saving some 7.62 x 39 Lapua brass to re-size for this latest project. First I ran all the new Hornady brass through the new die, then decided to re-size the Lapua "SK" brass. After "slicking it up" real well I began. It took quite a bit of effort to get the Lapua brass through the .264 LBC die.
      When I finally got it complete there is a small "band" or "belt" near the bottom of the brass. {Head stamp end} The diameter of the Belt area is .4435, which I see is a tight fit to the chamber. I've never had this happen on any brass I have ever re-sized to a different caliber. The diameter of the re-sized brass directly above the "belt" for lack of a better term, is .436. A difference of .0075. This is an AR type die so it will be small base. I have not yet fire formed the brass. I wanted to ask you all first.


      "When somebody gets something for nothing then somebody paid something and got nothing"

      Comment

      • LR1955
        Super Moderator
        • Mar 2011
        • 3355

        #18
        Originally posted by sniper20 View Post
        I am waiting on the rest of my parts to complete a build for my Grendel, but I have been in a quandry about the brass and ammo... Would it be a better option to buy 7.62 brass at .60/piece and fire form them, or pay the extra .15-.20/piece for the actual 6.5 Grendel brass? I was going to get Hornady brass and load them, but for the price of buying new brass, it will actually be a wash, if not cheaper to buy factory ammo and shoot that up for the brass... Or, if you fire form brand new brass, would it be a better bet?

        The issues I see coming with this is obviously the large primer vs the small primer and the "wasted" bullet to do the forming. I have thought about the corn meal and pistol powder method, or going with a "middle of the road" charge and seeing how accuracy is on an unformed piece. I have read many mixed reviews about doing both. Some say the corn meal is the way to go, others complain about it plugging up the gas system (I would leave mine apart for this, just cycling each round myself on a bare barrel).

        Do you guys think it would be more advantageous to get factory ammo and shoot it up for the brass? Or buy cheap brass and have it formed? Has anyone loaded up a "regular" load and shot for accuracy? If so, what were the results?
        I did a bunch of work with IMI and Winchester 7.62 X 39 brass when we were having problems finding Grendel brass.

        It is far more advantageous to buy factory loads than screw around with 7.62 X 39 brass.

        I did get some IMI stuff to shoot at the same speed as Grendel brass would. I used a bit less powder but due to the smaller capacity of the 7.62 X 39 brass, it was a moderately compressed load. The primer pocket opened up so much that the brass was one shot. Two if you count the fire forming load.

        I have never seen a difference in accuracy between any of the brass, Lapua, Hornady, PPU, or any of the 7.62 X 39 loads. However, I never shot any 7.62 X 39 loads past 200. The velocities were horribly slow if you used a load that would give you at least four shots before the primer pockets opened up too much. This is because you would have to use loads that were two or three grains less for the 7.62 X 39 brass.

        Never viewed it as wasting a bullet to fire form. I would use them at 200 to practice off hand and they worked just fine. Never gave up anything with them because even though their speeds were very slow, at 200 it really didn't matter. I used to blow out 22-250 brass to 6 XC at matches to 300 yards and never saw a degradation in accuracy. And if you guys think 7.62 X 39 brass looks rough when it is run through a Grendel sizer, you ought to see 22-250 brass when run through a 6 XC sizer.

        We did the fire forming thing because we could not get Grendel brass. Not because it was better, cheaper, or anything else. We had no choice at the time if we wanted to shoot our Grendel rifles.

        Oh yes, I would probably not want to blow corn meal down a rifle barrel so if you decide to fire form, load with the minimum charge or a grain or two less, and get some practice in while fire forming.

        LR55

        Comment

        • LR1955
          Super Moderator
          • Mar 2011
          • 3355

          #19
          Originally posted by ironhorse18 View Post
          Hello again to all. I just received my order of Hornady 6.5 Grendel brass and a set of RBCS .264 LBC dies. I had been saving some 7.62 x 39 Lapua brass to re-size for this latest project. First I ran all the new Hornady brass through the new die, then decided to re-size the Lapua "SK" brass. After "slicking it up" real well I began. It took quite a bit of effort to get the Lapua brass through the .264 LBC die.
          When I finally got it complete there is a small "band" or "belt" near the bottom of the brass. {Head stamp end} The diameter of the Belt area is .4435, which I see is a tight fit to the chamber. I've never had this happen on any brass I have ever re-sized to a different caliber. The diameter of the re-sized brass directly above the "belt" for lack of a better term, is .436. A difference of .0075. This is an AR type die so it will be small base. I have not yet fire formed the brass. I wanted to ask you all first.


          "When somebody gets something for nothing then somebody paid something and got nothing"
          Put the sized 7.62 X 39 brass in the chamber. Let the bolt close on its own. Then extract the brass. It may stick a little so don't be surprised if it does. If it comes out with relatively little problem, load it and shoot it.

          LR55

          Comment

          Working...
          X