Howa Mini 22" Range Results, Chrono Data 123gr SST, 123gr AMAX, 129gr SST

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts
  • LRRPF52
    Super Moderator
    • Sep 2014
    • 8569

    Howa Mini 22" Range Results, Chrono Data 123gr SST, 123gr AMAX, 129gr SST

    So this is something I was supposed to have done much earlier this year, but I've been slowed down from a pretty heinous injury on one of our Boy Scouts activities back in May. Snapped my achilles tendon like tow strap giving out.

    Anyway, I haven't been shooting much, so I finally got out today to do some reviews as promised.



    I started with some ladders I had worked up earlier in the year.

    123gr SST
    Federal brass 1x fired 1.208" headspace to shoulder datum
    Rem 7 1/2 SRP
    Hodgdon's LEVERevolution
    COL: 2.250"
    Temp: 60˚F on range thermometer
    Chrony Beta Master 15ft from muzzle

    29.8 2453
    30.1 2465
    30.4 2499
    30.7 2517
    31.0 2534
    31.3 2596
    31.6 2608
    31.9 2605
    32.2 2658 (This averages 51,551psi in a SAAMI chamber.)


    129gr SST
    Lapua brass 1.215" headspace to datum
    Rem 7 1/2 SRP
    LEVERevolution
    COL: 2.310"
    60˚F

    Left string was shot first, then the right one
    29.3 2370 2407
    29.6 2393 2400
    29.9 2448 2405
    30.2 2453 2404
    30.5 2504 2453
    30.8 Error 2475
    31.1 2485 2512
    31.4 2530 2523
    31.7 2534 2545
    32.0 2572 2572

    31.2gr CFE / 123gr AMAX load
    2599
    2557
    2582
    2617
    2617
    2564
    2586
    2608
    2619
    2566
    AVG: 2592fps. (AVG chamber pressure with this load is 46,235psi. in a SAAMI chamber.)

    Hornady American Gunner 123gr BTHP
    2469
    2456
    2465
    2463
    2437
    AVG: 2458fps

    Everything fed fine from the mag even the 129gr SSTs at 2.310" COL. I think I would choose the 129gr SST load for hunting, didn't notice too much difference in recoil. Fun little rifle to shoot.

    All my primers have nice little dimples in them. I didn't see anything crazy going on with the brass, not that I rely on brass as a sign of excessive pressure, but I definitely still look at it. Even the Federal brass looks good.

    We'll see how it turns out after being run through the tumbler and de-primed.
    Last edited by LRRPF52; 11-29-2017, 03:35 PM.
    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
  • grayfox
    Chieftain
    • Jan 2017
    • 4295

    #2
    Glad to see you're able to get around a bit now after the injury!

    You took the powders a bit higher than I've seen in the howa, in another thread you said 31.4-31.7 might be where you want to be?
    "Down the floor, out the door, Go Brandon Go!!!!!"

    Comment

    • LRRPF52
      Super Moderator
      • Sep 2014
      • 8569

      #3
      If you look at the 31.4-31.7gr charges, they show initial signs of a possible node with the 129gr SST.

      I do pressure ladders first that will give some indication of a trend line with regards to how each incremental charge weight affects velocity.

      If I wanted to go back and fine-tune a load, I could start with 31.4 in .2 gr increments and chase it, or just call it good and load 31.5 or 31.6gr in 10rd strings and see what they do.

      Then play with seating depth.

      For a basic little hunting rifle, I wouldn't hesitate to just load 31.5gr and call it a day.

      This has a sporter profile barrel, so its intended use is for normal hunting distances I think. Here we can lean on velocity if we want, as vital zones are rather large, unless shooting for neck and head shots.

      I have a 20rd group from the rifle that included all of these shots that measures 2.2"x2.3", with a cluster in one area with at least 10 shots in it.

      I'll take the 31.5gr load most likely and see how it groups at 100yds and 200yds to determine what the probability of impact is within a certain cone, and record that data for the rifle as a potential go-to load for hunting.

      For the conditions I was in today, that load would give me expansion out to 575yds with 922ft-lbs.

      Assuming I have a 2 MOA load with the 31.5gr, and I get some field time with the rifle from positions out to 600yds, I would feel more comfortable with 400yd shots on game up to at least mulies.

      I currently would have no question about 200yd shots through the vitals, and the 129gr SST plows through really well, with rapid expansion.
      Last edited by LRRPF52; 11-26-2017, 02:31 AM.
      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

      • xlcc
        Warrior
        • Feb 2016
        • 210

        #4
        It is interesting with the 123SST and 31.3 grs. of LEVERevolution and your 123 AMAX with CFE and 31.2 grs. of powder the velocity is very close.I wonder how the accuracy will compare to your go to load of CFE?Do you think the pressures would be equivalent?

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #5
          Originally posted by xlcc View Post
          It is interesting with the 123SST and 31.3 grs. of LEVERevolution and your 123 AMAX with CFE and 31.2 grs. of powder the velocity is very close.I wonder how the accuracy will compare to your go to load of CFE?Do you think the pressures would be equivalent?
          There has been a suspicion for a while now that CFE223 is LEVERevolution with the Copper Fouling Eliminator added.

          The data between the 2 seems interchangeable.
          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

          • xlcc
            Warrior
            • Feb 2016
            • 210

            #6
            I don't have any 129SST bullets to compare to 123SST's but I was wondering why the difference in COL's?

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #7
              129gr SST is longer.

              Loading it longer increases the relative case volume compared to if I loaded it to 2.260".

              123gr AMAX, 123gr SST, 129gr SST, 140gr AMAX

              Last edited by LRRPF52; 11-27-2017, 02:12 PM.
              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

              • xlcc
                Warrior
                • Feb 2016
                • 210

                #8
                Nice picture comparisons of the different bullets.It looks to me that the 123SST could be seated to the same COL as the 129SST for more case volume.

                Comment

                • Joseph5
                  Warrior
                  • Oct 2012
                  • 370

                  #9
                  The 129 SST load in the mid 2500's will kill any animal that took it through the lungs. I would not hesitate to use it for elk hunting and just be mindful of shot placement.

                  Comment

                  • Singleshotsam
                    Bloodstained
                    • Jan 2016
                    • 38

                    #10
                    I just took a very large white tail ( ten point 250lb field dressed) he was moving at a good clip, stoped him in 30yds with a nosler 120gr on top of 31.3 of CFE 223. no exit hole on either shot, foot/lbs may not be as high as some but it all expended on the buck! The low recoil lit me get off 2 well placed shots in about 35yds of the opening, may be could have done same with larger caliber but not as easy.

                    Comment

                    • jason miller
                      Warrior
                      • Dec 2016
                      • 182

                      #11
                      Nice! Thanks for posting!

                      I think I've seen enough evidence that LVR or CFE produce top velocity in this little cartridge with bullets of 123 or heavier. LVR might be worth it to adjust powder charge for colder temps in hunting season. Has anyone ever done any temp stability testing in the Grendel with this powder? Some cartridge/powder combinations are more stable than others. It would be great if we're lucky enough that the Grendel/LVR/130 class of bullets is one of those combinations...

                      Comment

                      • LRRPF52
                        Super Moderator
                        • Sep 2014
                        • 8569

                        #12
                        Originally posted by jason miller View Post
                        Nice! Thanks for posting!

                        I think I've seen enough evidence that LVR or CFE produce top velocity in this little cartridge with bullets of 123 or heavier. LVR might be worth it to adjust powder charge for colder temps in hunting season. Has anyone ever done any temp stability testing in the Grendel with this powder? Some cartridge/powder combinations are more stable than others. It would be great if we're lucky enough that the Grendel/LVR/130 class of bullets is one of those combinations...
                        Yes, several have done temp sensitivity testing and CFE is pretty temp sensitive, being a double-based ball powder.

                        With the benefit of high density and tons of forgiveness, you also get velocity shifts.

                        AR-Comp has probably the least temp sensitivity, but is faster-burning, so you have to be very cautious with it under 123gr and higher.

                        We can also put temp sensitivity into perspective by considering what practical distances we're hunting at.

                        At 2500fps mv with 100yd zero, we have 5" of drop at 200yds. Worst case, let's say we drop 100fps down to 2400fps in extreme cold.

                        That gives us 5.5" of drop at 200yds, so well within the accuracy potential of the rifle.

                        Now at 400yds, 2500fps mv would give us -38" and 2400fps would be -42" of drop, so still well within the probability of error.

                        With a 200yd zero, it's 31" and 29". I've usually confirmed zero in the area I'm hunting with my party members, both in the US and in Europe, so I don't see the temp sensitivity being a factor for most hunters outside of Long Range hunters.
                        Last edited by LRRPF52; 11-28-2017, 08:30 PM.
                        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

                        • jason miller
                          Warrior
                          • Dec 2016
                          • 182

                          #13
                          I agree with all of that. The biggest problem I could see would be if one's rifle no longer grouped as well or impacted in correlation to their crosshairs with a big enough velocity/pressure loss. Akin to falling out of a "node"...

                          Comment

                          • grayfox
                            Chieftain
                            • Jan 2017
                            • 4295

                            #14
                            From other forums, the delta I've seen is 1 ft/sec per 1 deg F.... so for 70 down to 20 deg that would be a 50 ft/s difference...
                            Actually I've wondered about the Strelok default temp sensitivity setting of 1.3%... which would seem to be > 25 ft/sec per degree for 2500 ft/sec... unless I'm missing something.
                            "Down the floor, out the door, Go Brandon Go!!!!!"

                            Comment

                            • Cornbread
                              Warrior
                              • Dec 2015
                              • 288

                              #15
                              This. Find a large enough node with a temp sensative powder. I usually run a ladder test and if I get 3 charge weights .3 apart for rougly 1 grain that group together I load for the TOP of the node in warm weather. This will usually keep me in the node were poi does not change much. I have put 9 rounds from 3 different charge weights inside moa with the right load. I cringe when I see guys with a load that .3 grains difference changes the poi and group size dramatically. This is a recipe for disaster with a temp sensitive powder which most are to some extent.

                              Comment

                              Working...
                              X