123 amax BC

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  • cst
    Warrior
    • Jan 2014
    • 239

    123 amax BC

    I've read several old threads but no one really confirmed it.....what is the official BC for the 123 AMAX g1/g7? I've seen some guys saying the g1 listed is too high? I need some reliable numbers for 800 to 1000 yards
  • bwaites
    Moderator
    • Mar 2011
    • 4445

    #2
    Originally posted by cst View Post
    I've read several old threads but no one really confirmed it.....what is the official BC for the 123 AMAX g1/g7? I've seen some guys saying the g1 listed is too high? I need some reliable numbers for 800 to 1000 yards
    Official G1 is .510, I've actually found the G1 to be closer to .490 with my loads.

    I've gotten my best results using a G7 of .253, though.

    Comment

    • Kendoist4162
      Bloodstained
      • Jun 2015
      • 38

      #3
      Hornady has the G1 BC listed as .510 on their site but no G7 number. There is a VERY good discussion thread on the G1 vs. G7 "thing" on Snipers Hide. Dunno if links are allowed to other places like SH, but it is easy to find. Edited - listen to the man above too. ;-)

      Comment

      • bwaites
        Moderator
        • Mar 2011
        • 4445

        #4
        Originally posted by Kendoist4162 View Post
        Hornady has the G1 BC listed as .510 on their site but no G7 number. There is a VERY good discussion thread on the G1 vs. G7 "thing" on Snipers Hide. Dunno if links are allowed to other places like SH, but it is easy to find. Edited - listen to the man above too. ;-)
        Appropriate links are fine!

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #5
          If anyone has the Applied Ballistics 2nd Edition, he might have done the BC analysis on it. Those are pretty authoritative. His analysis on the 123gr Sierra Match King showed that it was actually much higher than Sierra stated, even with their speed range variation. The 123gr SMK ended up being .522, not the listed .510 for G1. G7 was higher too, I think .260.

          Someone on the forum should have the books and be able to look it up. He put out some recent ones with 400 different projectiles tested with live fire, not theoretical drag modeling and shape analysis only.
          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

          • acourvil
            Warrior
            • Dec 2013
            • 112

            #6
            Here are Litz' numbers for the 123 SST, which I believe is the same (or at least very close) to the AMAX:

            G1
            overall .462
            below 1500 .406
            2000-1500 .432
            2500-2000 .467
            3000-2500 .491
            Above 300 .526

            G7
            overall .236
            below 1500 .228
            2000-1500 .229
            2500-2000 .235
            3000-2500 .244
            above 3000 .249

            Comment

            • cst
              Warrior
              • Jan 2014
              • 239

              #7
              Those numbers look awfully low...anyone shoot amax to 1000 and compare data?

              At 2510 ,70 deg at 1000'...it's subsonic at 960yards. .I was getting supersonic with the 123 Scenars to almost 1100yards...
              Last edited by cst; 10-01-2015, 05:46 PM.

              Comment

              • tasty_chicken
                Bloodstained
                • Jul 2015
                • 53

                #8
                Can someone educate me on the difference between G1/G7? I only see 123 AMAX G1.

                The page you are looking for could not be located. We're sorry, but it appears the page you have requested is no longer available. Please check the URL and try again....

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                • cst
                  Warrior
                  • Jan 2014
                  • 239

                  #9
                  Has anyone shot 123 amax to 1000 yards and beyond? Or do I have to go back to scenars?

                  Comment

                  • lawndartmike
                    Bloodstained
                    • Mar 2015
                    • 53

                    #10
                    A good video on the difference between G1 and G7: https://www.youtube.com/watch?v=gjzs79kDr6E

                    Comment

                    • bwaites
                      Moderator
                      • Mar 2011
                      • 4445

                      #11
                      Originally posted by cst View Post
                      Has anyone shot 123 amax to 1000 yards and beyond? Or do I have to go back to scenars?
                      Factory loads in Competition shot very well for me. I was able to shoot 10s and X's when I didn't miss the wind!

                      Comment

                      • cst
                        Warrior
                        • Jan 2014
                        • 239

                        #12
                        So if Litz is correct with the G7 on the SSTs and I use .244 as my BC....its subsonic by 980yards...SUKS.

                        Comment

                        • go4shoot
                          Unwashed
                          • Jul 2015
                          • 12

                          #13
                          That bc is quite disappointing. I'm wondering if I'm better of with the 129 sst. Anyone know what the fps expansion threshold is on the 129 is?

                          Comment

                          • LRRPF52
                            Super Moderator
                            • Sep 2014
                            • 8569

                            #14
                            Originally posted by cst View Post
                            So if Litz is correct with the G7 on the SSTs and I use .244 as my BC....its subsonic by 980yards...SUKS.
                            The 123gr SST is not the same bullet as the 123gr AMAX. The ogives are different, and the cannelure is not present on the 123gr AMAX.

                            When I have used the stated BC on the 123gr AMAX, I was shooting out to 1200yds, and that's with the actual barometric pressure, temperature, and altitude entered into my ballistics program. I was at 4400ft elevation. One thing about tighter rifling is that it spins the pill so much that they stay stable through transonic, so you don't get erratic trajectory after the maximum ordinate like you do with loose twists.

                            Even still, I'm supersonic out to 1318yds in those conditions.
                            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

                            • acourvil
                              Warrior
                              • Dec 2013
                              • 112

                              #15
                              Originally posted by LRRPF52 View Post
                              The 123gr SST is not the same bullet as the 123gr AMAX. The ogives are different, and the cannelure is not present on the 123gr AMAX.
                              Interesting, that's the first time I've heard that. Hornady's web site lists both as having a secant ogive profile and as having .510 G1 BCs and .252 sectional density (but doesn't give any dimensional details for the 123g versions)

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