Boxed ELD pierced primer

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  • HillclimberCR500
    Bloodstained
    • Jun 2016
    • 54

    #16
    Picked up a few boxes of the Hblack and also had a few perced primers lot # 3163589. Primers were also a bit flat this happened once with the sst also. I had 1 SST not fire at all. Seemed to shoot OK though. didn't chrono it yet cuz it was 30 degrees and I didn't feel like pulling everything out

    Comment

    • Nachunter
      Unwashed
      • Sep 2016
      • 12

      #17
      Guys just wanted to give a heads up. I chrono'd a few different lots for of Hornady ELD today. The lot mentioned by 1911man, LOT# 316820, did shoot about 140FPS faster than the other 2. Six shots of each box.
      #3163820 - AVG FPS - 2623
      #3170694 - AVG FPS - 2477
      #3170405 - AVG FPS - 2483
      I did have some protrusion around primers holes on Lot #3163820.

      Comment

      • LRRPF52
        Super Moderator
        • Sep 2014
        • 8569

        #18
        What's the COL on these factory cartridges?
        NRA Basic, Pistol, Rifle, Shotgun, RSO

        CCW, CQM, DM, Long Range Rifle Instructor

        6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

        www.AR15buildbox.com

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        • just_john
          Chieftain
          • Sep 2012
          • 1565

          #19
          Some years ago, Hornady had a manufacturing issue where the bullet ogive had two significantly different profiles within the same lot numbers. Bullet weight was the same, just the shape was different. These were .270 boxed rounds. But, they may have done it again.

          Comment

          • kmon
            Chieftain
            • Feb 2015
            • 2095

            #20
            Originally posted by Nachunter View Post
            Guys just wanted to give a heads up. I chrono'd a few different lots for of Hornady ELD today. The lot mentioned by 1911man, LOT# 316820, did shoot about 140FPS faster than the other 2. Six shots of each box.
            #3163820 - AVG FPS - 2623
            #3170694 - AVG FPS - 2477
            #3170405 - AVG FPS - 2483
            I did have some protrusion around primers holes on Lot #3163820.
            Time to call Hornady. give them that information and this thread information. 140fps higher from one lot over 2 other lots of ammo is not the normal. Be it bullet ogive, seating depth, powder...

            Comment

            • waveslayer
              Warrior
              • Jan 2013
              • 239

              #21
              Guys, I haven't been on here recently and i just saw this post this morning. I knocked the dust off my Grendel's yesterday. I had picked up some Hornady Black ammo with the 123 ELD-M bullets.

              I had 1 pierced primer out of 20 shots with 3 having pressure issues. I will pull the lot number this morning. Using my 18" Satern II barrel I chronoed these at 2435 fps

              Comment

              • Nachunter
                Unwashed
                • Sep 2016
                • 12

                #22
                I didn't measure COL, but all lots had the same BTOG of 1.655" with my instruments. So, I'm thinking this is a powder issue more that bullet variance issue. Factory AMAX has a slightly longer BTOG of 1.657".


                I ended up shooting the entire box. No pierced or blown primers, but they were definitely hot. #3820 shot about 2-4" higher than other lots @400yds, and group size around 2 MOA. The Extreme Spread of 6 shots over the chrony was 39fps (2601-2640), which I think is pretty high for Hornady match ammo. ES of 6 shots from Lot #0694 was 21fps (2468-2489). The plus side is, I now know that my gun does not like this velocity node.

                Side note, Factory AMAX shoots AVG 2532FPS out of my gun.
                Last edited by Nachunter; 04-03-2017, 03:38 AM.

                Comment

                • waveslayer
                  Warrior
                  • Jan 2013
                  • 239

                  #23
                  My ammo lot is lot#81528
                  Out of a 24" barrel velocity was 2555.56 , ES=44, SD=18.2
                  Out of a 18" barrel velocity was 2434, ES= 51, SD=12.3
                  I will call Hornady tomorrow on it.

                  Comment

                  • LRRPF52
                    Super Moderator
                    • Sep 2014
                    • 8569

                    #24
                    Originally posted by waveslayer View Post
                    My ammo lot is lot#81528
                    Out of a 24" barrel velocity was 2555.56 , ES=44, SD=18.2
                    Out of a 18" barrel velocity was 2434, ES= 51, SD=12.3
                    I will call Hornady tomorrow on it.
                    I don't see anything alarming at all with those numbers. They're pretty slow actually.

                    I just noticed that you are using a Satern barrel.

                    Can you please measure your bolt length and face depth. I think I know what the problem is-have seen it before.
                    NRA Basic, Pistol, Rifle, Shotgun, RSO

                    CCW, CQM, DM, Long Range Rifle Instructor

                    6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                    www.AR15buildbox.com

                    Comment

                    • Commander184
                      Bloodstained
                      • Nov 2016
                      • 47

                      #25
                      Originally posted by LRRPF52 View Post
                      I don't see anything alarming at all with those numbers. They're pretty slow actually.

                      I just noticed that you are using a Satern barrel.

                      Can you please measure your bolt length and face depth. I think I know what the problem is-have seen it before.

                      LRRP is correct it's goin to be in the headspace.

                      I once said no it can't be wrong the bolt came head spaced from where I bought it. Well they were wrong.

                      This sounds like too much head space

                      Comment

                      • LRRPF52
                        Super Moderator
                        • Sep 2014
                        • 8569

                        #26
                        I don't suspect headspace. I suspect firing pin protrusion, hence the pierced primers.

                        If you don't use a real Grendel bolt, then you are likely to get pierced primers.

                        With the .136" bolt face depth, you need to add .010"-.011" on the tail of the bolt when using standard firing pins, otherwise you get increased risk of pierced primers.

                        This is why 6.5 Grendel bolts are spec'd from scratch, not only from specific alloy, but to dimensions that are impossible to create from a 5.56 bolt.

                        Some of the imitation bolts I've seen or have had people measure are even shorter than 2.800"-standard for 5.56, combined with a deeper .136" face depth. Some have been 2.795" even, which is .005" short for a 5.56 NATO even.

                        Add a firing pin to that, and you will have excessive pin protrusion.

                        If you look at the basic and advanced mechanical engineering for the components to get them to work well inside of the AR15, there are some critical dimensions that need to be adhered to.

                        Face depth and bolt length are probably the biggest ones, along with processes for the bolt and extractor metallurgy, followed by the chamber and barrel extension specs and attachment.

                        I would hope that shops aren't just reading the need for .136" face depth, and ignoring the make-up for that on the tail for correct FP protrusion, but we have seen it a lot actually.

                        Check your firing pin tip to see if there is a crater on it. I have seen that before too, from flame-cutting of the plasma leakage through the pierced primer.

                        Imagine a micro blow torch with 50,000psi behind it, fed by slow-burning rifle powder, with a shape-charged chamber directing the flame against the firing pin head.
                        NRA Basic, Pistol, Rifle, Shotgun, RSO

                        CCW, CQM, DM, Long Range Rifle Instructor

                        6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                        www.AR15buildbox.com

                        Comment

                        • waveslayer
                          Warrior
                          • Jan 2013
                          • 239

                          #27
                          I haven't had a chance to measure my bolt face yet. My bolt is from PF precision and AA. I will measure it soon, when works settles down and I can get home at a decent time.

                          Comment

                          • LRRPF52
                            Super Moderator
                            • Sep 2014
                            • 8569

                            #28
                            All my bolts from AA and PF are .136"/2.810".
                            NRA Basic, Pistol, Rifle, Shotgun, RSO

                            CCW, CQM, DM, Long Range Rifle Instructor

                            6.5 Grendel Reloading Handbooks & chamber brushes can be found here:

                            www.AR15buildbox.com

                            Comment

                            • Garymc
                              Unwashed
                              • Feb 2016
                              • 12

                              #29
                              I just ran across this post and had 3 pierced primers out of a box of the eld black ammo lot 3163589. I chronographed the last 6 rounds in the box with zero issues. Velocity average for 3 shots each was 2563 and 2569 with an es/sd of 12/6 and 15/7 out of a 24" PF chambered Bartlein barrel I have 4 more boxes in the same lot. I have seen the same isolated issue with the sts

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                              • waveslayer
                                Warrior
                                • Jan 2013
                                • 239

                                #30
                                has anyone reached out to Hornady about this?

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