Lrrpf52

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  • mseric
    #1

    Lrrpf52

    Sorry 8208 XBR is not in QL data base yet.

    Code:
     Cartridge          : 6.5 mm Grendel
Bullet             : .264, 100, Nosler BalTip 26100
Cartridge O.A.L. L6: 2.250 inch or 57.15 mm
Barrel Length      : 16.0 inch or 406.4 mm
Powder             : Ramshot TAC

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step    Fill. Charge   Vel.  Energy   Pmax   Pmuz  Prop.Burnt B_Time
 %       %    Grains   fps   ft.lbs    psi    psi      %        ms

-20.0   77    24.00   2030     915   26463   7496     80.6    1.187
-18.0   79    24.60   2082     963   28173   7777     82.0    1.155
-16.0   81    25.20   2134    1012   29995   8057     83.4    1.124
-14.0   83    25.80   2187    1062   31939   8334     84.7    1.094
-12.0   85    26.40   2240    1114   34013   8607     86.0    1.065
-10.0   87    27.00   2293    1168   36230   8876     87.3    1.037
-08.0   89    27.60   2347    1223   38596   9140     88.5    1.007
-06.0   91    28.20   2400    1279   41130   9398     89.7    0.977
-04.0   93    28.80   2454    1338   43842   9649     90.8    0.948
-02.0   95    29.40   2509    1398   46745   9892     91.9    0.920  ! Near Maximum !
+00.0   97    30.00   2563    1459   49860  10127     92.9    0.893  ! Near Maximum !
+02.0   99    30.60   2618    1522   53188  10353     93.8    0.867  !DANGEROUS LOAD-DO NOT USE!
+04.0  101    31.20   2673    1586   56736  10567     94.7    0.842  !DANGEROUS LOAD-DO NOT USE!
+06.0  103    31.80   2728    1653   60541  10771     95.5    0.818  !DANGEROUS LOAD-DO NOT USE!
+08.0  105    32.40   2783    1720   64630  10963     96.3    0.794  !DANGEROUS LOAD-DO NOT USE!
+10.0  107    33.00   2839    1789   69031  11141     97.0    0.772  !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba     97    30.00   2709    1630   59733  10402     98.0    0.826  !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba     97    30.00   2383    1261   40605   9415     84.4    0.979
    Tags: None
  • LRRPF52
    #2
    Thank you sir! Interesting, since I have worked all the way up into the "DANGEROUS LOADS". I loaded 30.0gr, 30.5gr, 31.0gr, & 31.5gr of TAC under the 100gr NBT. QL says I'm in bad territory there I guess, like into 53,000-almost 60,000 psi. That is a huge jump in pressure from 30.6gr-31.8gr.

    For the 16" barrel, the long family Optimal Barrel Time nodes are listed as:
    0.5527
    0.6096
    0.6879
    0.7458
    0.8232
    0.8821
    0.9585

    http://the-long-family.com/OBT%20Table.pdf


    Looking at those with that QL chart as a pressure reference, it looks like 0.8821 will be the best OBT from the above list to use if we want to stay around 50,000psi, so we're looking at a charge between 30.0 and 30.6gr.

    What if we plug in the above OBT times into QL to generate the data?

    I wonder what pressures I'm into with the 120gr SMK on 30.0gr of TAC. It seems like they are holding strictly to the 50,000psi Grendel/AR15 cut-off, which is probably what is spec'd in SAAMI.

    Comment

    • Tooreal
      #3
      Hello mseric & LRRPF52,

      I was wanting to get your opinion on a matter that interests me because of safety matters for myself.. I have worked up some really accurate loads using Hornady Brass, but when I go to Lapua new brass should I decrease my powder charge by a certain percent? I started using 2% less powder in the new Lapua brass because of the difference in shot placement & action problems, and it began to get better.. But is there a chart or calculation that I can go by for going from Hornady to Lapua Brass when loading the same bullet, primer & powder in the 2 different cases??

      Thanks in advance
      Eric

      Comment

      • txgunner00
        Chieftain
        • Mar 2011
        • 2070
        #4
        I just called the QL people and they said the new version has most of the new powders in it- 8208, AR comp, & others. I'm thinking about buying it myself now.
        NRA life, GOA life, SAF, and TSRA

        "I ask, Sir, what is the militia? It is the whole people, except for a few public officials. To disarm the people is the best and most effectual way to enslave them."

        George Mason, co-author, 2nd Amendment.

        Comment

        • JASmith
          #5
          Originally posted by txgunner00 View Post
          I just called the QL people and they said the new version has most of the new powders in it- 8208, AR comp, & others. I'm thinking about buying it myself now.
          Was there any discussion of changes to either the underlying math model or to the default settings to do a better job of predicting the velocities and pressures when long bullets are used in short, fat cartridges like the Grendel?

          Comment

          • txgunner00
            Chieftain
            • Mar 2011
            • 2070
            #6
            No, I just asked about the powder.
            NRA life, GOA life, SAF, and TSRA

            "I ask, Sir, what is the militia? It is the whole people, except for a few public officials. To disarm the people is the best and most effectual way to enslave them."

            George Mason, co-author, 2nd Amendment.

            Comment

            • LRRPF52
              #7
              Originally posted by Tooreal View Post
              Hello mseric & LRRPF52,

              I was wanting to get your opinion on a matter that interests me because of safety matters for myself.. I have worked up some really accurate loads using Hornady Brass, but when I go to Lapua new brass should I decrease my powder charge by a certain percent? I started using 2% less powder in the new Lapua brass because of the difference in shot placement & action problems, and it began to get better.. But is there a chart or calculation that I can go by for going from Hornady to Lapua Brass when loading the same bullet, primer & powder in the 2 different cases??

              Thanks in advance
              Eric
              The book answer is of course to drop down by 10% whenever you change a component in your recipe. It's easy to assume that Lapua brass is stronger, and therefore one might conclude that it doesn't matter, but that fails to take into account the volume changes from one case to another.

              This is why I just stick with Lapua brass. After reading through the 24" barrel, 123gr AMAX, 8208 thread, I noticed that txgunner had some really bad pressure signs/beginnings of failures with Hornady brass that didn't show him any signs before. I think it was at 5 or 6 loadings that he had some beginning cracks that almost went complete case head separation. LR1955 advised many on the old site that you have to be careful when pushing this cartridge, as things can spike on you unexpectedly.
              Last edited by Guest; 03-03-2012, 04:14 PM.

              Comment

              • txgunner00
                Chieftain
                • Mar 2011
                • 2070
                #8
                Originally posted by LRRPF52 View Post
                The book answer is of course to drop down by 10% whenever you change a component in your recipe. It's easy to assume that Lapua brass is stronger, and therefore one might conclude that it doesn't matter, but that fails to take into account the volume changes from one case to another.

                This is why I just stick with Lapua brass. After reading through the 24" barrel, 123gr AMAX, 8208 thread, I noticed that txgunner had some really bad pressure signs/beginnings of failures with Hornady brass that didn't show him any signs before. I think it was at 5 or 6 loadings that he had some beginning cracks that almost went complete case head separation. LR1955 advised many on the old site that you have to be careful when pushing this cartridge, as things can spike on you unexpectedly.

                That was actually Lapua (AA) brass on the 4th or 5th loading. Shooting on a 115 degree day laying in the sun is what pushed it over the edge. I backed off .2 gr and now have 8 loadings on that same batch of brass.
                Last edited by txgunner00; 03-03-2012, 04:04 PM.
                NRA life, GOA life, SAF, and TSRA

                "I ask, Sir, what is the militia? It is the whole people, except for a few public officials. To disarm the people is the best and most effectual way to enslave them."

                George Mason, co-author, 2nd Amendment.

                Comment

                • LRRPF52
                  #9
                  My bad. I'm a biased proponent of Lapua, admittedly. I had one piece of brass that showed that ridge at the base, and I retired it from the population. Just watched your Helo video, which just looks like more fun than a person should be allowed to have........

                  Except in America!

                  Comment

                  • hugh
                    #10
                    I've done all my testing with hornedy brass and arrived at a load that worked prity good...
                    I also have been sitting on some AA brass, saving for boomershoot...
                    So with hornedy brass, 27.5gr a-comp, 123gr amax and fed gm primed l managed 2518 average.
                    Same load in AA brass average 2465, same temperature. The groups spread to over one moa ...
                    So I made 4 sets of 5 starting at 27.7 in tenths up to 28.0... I did see some improvement @ 27.9 with average
                    Velocity of 2540 . All this makes me wonder if the smaller flash hole made the difference.

                    Comment

                    • hugh
                      #11
                      I've done all my testing with hornedy brass and arrived at a load that worked prity good...
                      I also have been sitting on some AA brass, saving for boomershoot...
                      So with hornedy brass, 27.5gr a-comp, 123gr amax and fed gm primed l managed 2518 average.
                      Same load in AA brass average 2465, same temperature. The groups spread to over one moa ...
                      So I made 4 sets of 5 starting at 27.7 in tenths up to 28.0... I did see some improvement @ 27.9 with average
                      Velocity of 2540 . All this makes me wonder if the smaller flash hole made the difference.

                      Comment

                      • txgunner00
                        Chieftain
                        • Mar 2011
                        • 2070
                        #12
                        Originally posted by LRRPF52 View Post
                        My bad. I'm a biased proponent of Lapua, admittedly. I had one piece of brass that showed that ridge at the base, and I retired it from the population. Just watched your Helo video, which just looks like more fun than a person should be allowed to have........

                        Except in America!
                        No problem. I'm a Lapua fan too but any brass would have been damaged in that situation. I lucky none came apart. The rest are are holding up fine but I do check the inside of every case with a dental pick every time I load them.

                        The helo hunt was the most fun I had in a long time. I can't wait to do it again. You should come down yourself some time.

                        God bless Texas!

                        God bless America!
                        NRA life, GOA life, SAF, and TSRA

                        "I ask, Sir, what is the militia? It is the whole people, except for a few public officials. To disarm the people is the best and most effectual way to enslave them."

                        George Mason, co-author, 2nd Amendment.

                        Comment

                        • LRRPF52
                          #13
                          I'm very motivated to come down and do a pest eradication like that. Trying to see where it will fit in this year's schedule and no dice so far, as I'll be busy finishing my degree, going to BoomerShoot, and then overseas for a while all within the next few months through the summer. Can you do this in the fall down there?

                          I saw some ads for guided hog hunts here in Utah on the board at Sportman's Warehouse, but nothing would compare to the helo hunt. If we could just mount the Dillons on the helos, and go to town...that would be the ultimate bucket list event.

                          Comment

                          • txgunner00
                            Chieftain
                            • Mar 2011
                            • 2070
                            #14
                            Hog are open to hunt year round by pretty much any method.

                            This guy makes me jealous...

                            ERROR: The request could not be satisfied
                            http://s842.photobucket.com/albums/zz344/hrt4me/?action=view&current=M60E4inHuey.mp4
                            NRA life, GOA life, SAF, and TSRA

                            "I ask, Sir, what is the militia? It is the whole people, except for a few public officials. To disarm the people is the best and most effectual way to enslave them."

                            George Mason, co-author, 2nd Amendment.

                            Comment

                            • Hoot
                              #15
                              Originally posted by txgunner00 View Post
                              I just called the QL people and they said the new version has most of the new powders in it- 8208, AR comp, & others. I'm thinking about buying it myself now.
                              Here's 8208XBR. Anyone have the version with the AR-Comp entry? I'd kill for just that one powder definition as I'm quite fond of it.

                              "IMR 8208 XBR ","3920","1.2355","1.620","0.6250","0.6641","0.401 ","1.4540","0.920","","","","","","","","","",""," ","22AUG10"

                              Hoot

                              Comment

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