SC DNR Study

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  • LRRPF52
    Super Moderator
    • Sep 2014
    • 8569

    SC DNR Study

    I've posted this before, but thought it would be interesting for those that haven't seen it.





    The South Carolina DNR has published an interesting article by wildlife biologist Charles Ruth, based on an extensive SCDNR deer hunting study. This article can be found at http://www.dnr.sc.gov/wildlife/deer/articlegad.html
    NRA Basic, Pistol, Rifle, Shotgun, RSO

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  • mdram
    Warrior
    • Sep 2016
    • 941

    #2
    why not use muzzle energy as a grouping?
    just some targets for printing
    https://drive.google.com/drive/folde...xQ?usp=sharing

    Comment

    • LRRPF52
      Super Moderator
      • Sep 2014
      • 8569

      #3
      Originally posted by mdram View Post
      why not use muzzle energy as a grouping?
      My main response to that is that muzzle energy does not correlate to energy on-target, mainly because of BC, then velocity.

      Look at the ballistics between an 11.5" Grendel with the 129gr ABLR and a 20" .30-30 with a 150gr RN, for example.

      Or a 7-08 with a modern bullet with long boat tail and a 7mm Mag with a flat-based 175gr SP. 7mm Mag blows all its energy within the 1st 100yds with that draggy bullet, making the advantages of a larger case and pains of recoil amount to nothing but negatives. A lot of the factory 175gr 7mm Mag loads use a crappy FB bullet with a BC around .400, which is easily beaten by 7mm-08 with a good bullet.

      This is something that has really changed since the times that many of us that are in our 40s or older grew up with.

      Everything was measured by looking at bullet weight and speed at the muzzle. We had to rely on manufacture-printed ballistic data on the boxes if they had it, and we had no way of knowing what the retained energy was or expansion thresholds, without doing some kind of terminal ballistics tests at distance. A lot of us just shot water jugs and watched them either vaporize, peel open, or get ice-picked.

      I remember looking at the ballistics tables in the more advanced Sniper manuals that I had in the Army-particularly the SF one. Looking at M118 trajectory and wind, I wondered how they had generated those tables, figuring it was either from computers at Aberdeen or White Sands. We just had them for reference without a way to measure our mv and get actual data for the guns other than shooting them at different distance and recording it in a log book.

      Along comes PDAs, then smart phones, and ballistic apps. Chronographs became more widely-available in the 1980s and 1990s. Handheld weather stations started coming on-board in the 1990s.

      We could now get real data for mv, barometric pressure, temperature, and enter these into the program to get much more accurate predictions for the conditions we were in.

      One problem we started to see is that published BC values for bullets was based on theoretical drag models that had certain bullet shapes and limited ranges as assumptions, like flat-based bullets being shot out to 200, 400, and 600yds.

      We were shooting boa tail bullets farther than that, although for hunting purposes, the G1 drag model works fine within 400yds. Time of Flight is so short, not a lot can happen, and most rifle trajectories are very similar within close range.

      Now that we are getting more accurate expansion threshold data from bullet makers, we know the BCs, and can chronograph our rifles, we can understand where our expansion threshold is exactly.

      A lot of this is covered in Volume II, with a table showing the effective ranges and point blank zeroes for different 6.5 Grendel barrel lengths with the 123gr SST.

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      Comment

      • mdram
        Warrior
        • Sep 2016
        • 941

        #4
        ok, understood
        but there are so many variables.
        I have shot deer @ 50 yds with a 30-06 that ran over 100yds (both heart and lungs destroyed)
        and shot deer @ 300yds with the same rifle and ammo that were DRT (neck shot)

        i have also helped clean deer where a 7mm mag passes between both rib cages, with hardly any expansion, requiring a second shot

        shot placement has alot do with it, as does plain luck in hitting the correct vitals
        just some targets for printing
        https://drive.google.com/drive/folde...xQ?usp=sharing

        Comment

        • LRRPF52
          Super Moderator
          • Sep 2014
          • 8569

          #5
          The higher velocity cartridges can cause a lot of erratic behavior, and some animals just don't like to be dead.

          Others seem like they are just waiting for you to end it and lay down.

          A neck shot through the actual spinal cord is going to have very predictable results.

          The easy answer is using a center fire rifle with sufficient projectile construction that has very low recoil, the tighter the twist rate, the better. If you can get trigger time with it without recoil and muzzle blast-induced flinching, with easy hits in the vitals something you have a lot of confidence in, your success rate will be much higher.

          I think that's why the .25-06 does so well in the absence of a .264" in the study. .25-06 has such little recoil, but still spits a 117-120gr out on a flat trajectory straight through what you aim it at, with the ability to see your own hits often. It's not a particularly efficient cartridge since the powder column is way longer than it needs to be for the speed it gets, and it uses a long action.

          It would have been interesting to see how a 6.5x55 would have factored in the SC DNR study, but we can compare some of the stats to the "Knock-Down" Survey we have here.
          NRA Basic, Pistol, Rifle, Shotgun, RSO

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

          www.AR15buildbox.com

          Comment

          • mdram
            Warrior
            • Sep 2016
            • 941

            #6
            i have found that trigger time is a big factor

            many of the deer i hear about running longer distances are from people that shoot very seldom
            usually a couple to verify sight in(if they even do that) and then 1 at the deer.

            you know those guys
            just some targets for printing
            https://drive.google.com/drive/folde...xQ?usp=sharing

            Comment

            • LRRPF52
              Super Moderator
              • Sep 2014
              • 8569

              #7
              Originally posted by mdram View Post
              i have found that trigger time is a big factor

              many of the deer i hear about running longer distances are from people that shoot very seldom
              usually a couple to verify sight in(if they even do that) and then 1 at the deer.

              you know those guys
              Yes. With optics from War Mart, non-bedded bases, no correct torque specs on scope rings, no loc tite on rings, Remington Core Lokts.
              NRA Basic, Pistol, Rifle, Shotgun, RSO

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

              www.AR15buildbox.com

              Comment

              • Hunter307
                Bloodstained
                • Jan 2017
                • 77

                #8
                Originally posted by LRRPF52 View Post
                Remington Core Lokts.
                lol I was just looking the other day on midwayusa to see if Remington made a .264 120gr corelokt bullet. Thought it might just be perfect for the Grendel based off of velocity numbers.

                Comment

                • LRRPF52
                  Super Moderator
                  • Sep 2014
                  • 8569

                  #9
                  That's how I started out with the .270 Winchester as a kid. Learned the hard way about bedding scope bases and loc-titng rings when I lost my zero unexplainably.

                  I had the rifle dialed-in perfectly, then started working out my distance trajectory with it using target stands spaced at 300-500yds. Into my 2nd box of ammo, I wasn't getting hits anymore.

                  Brought it back to 100yds, shotgun pattern. Huh?

                  Took to gunsmith. "Your scope is loose. You need the bases and rings Loc-tited. We'll take care of it, no big deal, and bore sight you as well for $25."
                  NRA Basic, Pistol, Rifle, Shotgun, RSO

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

                  www.AR15buildbox.com

                  Comment

                  • Double Naught Spy
                    Chieftain
                    • Sep 2013
                    • 2560

                    #10
                    Well, that was an interesting read. The author was working with a highly dubious set of data and tried to make sense out of the information. By highly dubious, I am fairly certain based on my own experience in dealing with hunters that the distances stated are often incongruent with reality.

                    I found it interesting that the author examined shot placement and running and caliber and running, but not caliber and shot placement relative to running. To conclude, as he did, that caliber made no difference is not really supported by the notion of solely comparing caliber and whether or not the animal ran, particularly given that he had already demonstrated that shot placement had a lot do do with whether or not the animal ran. Same for bullet performance. The same would go for factory rifle versus custom rifle, although I doubt the rifle type would have much to do with whether or not a deer ran after being shot.

                    The only three conclusions I feel confident from the report are that people are less likely to hit and recover deer shot at longer distances, that dogs are beneficial in helping find deer, and that rapidly expanding bullets are better performers.
                    Kill a hog. Save the planet.
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                    Comment

                    • FLS
                      Bloodstained
                      • Oct 2015
                      • 30

                      #11
                      I know Mr Ruth. Hes a Biologist, not a ballistic expert. He helped us with our management plan. We got 50 antleress tags and about as many depredation permit a year for th property I hunted for 10 years. With only 5 member I got to shoot a lot of deer and experiment. Honestly there was very little difference between most standard deer cartridges. The most dynamic kills were lighter bullets at high velocity that managed to stay together. My favorite was a 25-06 shooting a 115 ballistic tip or 117 Sierra about 3000 fps. I shot well over 100 deer with this combo and none ever went mor than a few steps with a hit to the vitals. I wasn't shooting a Grendle then but did shoot a bunch with a 6.8. The 95 gr TTSX and 110 Accubond did well with the 110 Sierras close behind. The small capacity cartridge didn't have the visible,violent impact on deer that the faster round did but still was very lethal. I'd expect the Grendel to be about the same.

                      Comment

                      • LRRPF52
                        Super Moderator
                        • Sep 2014
                        • 8569

                        #12
                        Originally posted by Double Naught Spy View Post
                        Well, that was an interesting read. The author was working with a highly dubious set of data and tried to make sense out of the information. By highly dubious, I am fairly certain based on my own experience in dealing with hunters that the distances stated are often incongruent with reality.

                        I found it interesting that the author examined shot placement and running and caliber and running, but not caliber and shot placement relative to running. To conclude, as he did, that caliber made no difference is not really supported by the notion of solely comparing caliber and whether or not the animal ran, particularly given that he had already demonstrated that shot placement had a lot do do with whether or not the animal ran. Same for bullet performance. The same would go for factory rifle versus custom rifle, although I doubt the rifle type would have much to do with whether or not a deer ran after being shot.

                        The only three conclusions I feel confident from the report are that people are less likely to hit and recover deer shot at longer distances, that dogs are beneficial in helping find deer, and that rapidly expanding bullets are better performers.
                        I caught those too. I also noticed the sample size for .25 caliber is relatively smaller than the rest of the calibers. It would have been nice to know the actual cartridges and projectile weights.

                        I still place a lot of emphasis on recoil though, combined with the other factors. Lower recoil builds confidence and allows more trigger time, which increases hit probability into the vitals.
                        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

                        • howl
                          Warrior
                          • Nov 2015
                          • 236

                          #13
                          So....softer bullets are better for deer, no matter the cartridge you have to hit your mark for it to work, and if you shoot for the neck you'll find it on the spot or not at all. Sounds about right!

                          Comment

                          • rickt300
                            Warrior
                            • Jan 2017
                            • 498

                            #14
                            The study, though interesting does point to the fact that animals do not act the same to various shot placement. Typically I don't shoot at running animals and it has been several years since a deer has run more than 50 yards after I shot it through the ribs. I often use Ballistic Tips in various cartridges and they do seem to kill quickly as do Sierra Gamekings.

                            Comment

                            • pajasonc
                              Warrior
                              • Dec 2016
                              • 203

                              #15
                              Originally posted by Double Naught Spy View Post
                              Well, that was an interesting read. The author was working with a highly dubious set of data and tried to make sense out of the information. By highly dubious, I am fairly certain based on my own experience in dealing with hunters that the distances stated are often incongruent with reality.

                              I found it interesting that the author examined shot placement and running and caliber and running, but not caliber and shot placement relative to running. To conclude, as he did, that caliber made no difference is not really supported by the notion of solely comparing caliber and whether or not the animal ran, particularly given that he had already demonstrated that shot placement had a lot do do with whether or not the animal ran. Same for bullet performance. The same would go for factory rifle versus custom rifle, although I doubt the rifle type would have much to do with whether or not a deer ran after being shot.

                              The only three conclusions I feel confident from the report are that people are less likely to hit and recover deer shot at longer distances, that dogs are beneficial in helping find deer, and that rapidly expanding bullets are better performers.
                              Agree completely.

                              Comment

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