Need New Bullets for 65G!

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  • BluntForceTrauma
    Administrator
    • Feb 2011
    • 3897

    #31
    When using the Bullet Drag Calculator, I try to mimic the shape of a hybrid ogive so in the Secant Radius box I enter 16. Not only is the bullet sleeker, but it's lighter so velocity goes up.

    Try these parameters: Bullet diameter = 0.264 / Length 1.25 / Nose 0.740 / Meplat 0.020 / Drive-band 0.264 / Base 0.220 / Boat-tail angle 5.9 / Boat-tail length .210 / Secant 16 / Weight 96 / Density 8.61. See attached.

    Also wondering if a bigger polymer tip is possible, something like the Winchester XP? See attached.
    Attached Files
    :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

    :: I Drank the Water :: Revelation 21:6 ::

    Comment

    • Makerbullets
      Unwashed
      • Mar 2017
      • 6

      #32
      A bigger tip is possible. It would take a while for us to build a new mold. The larger tip will likely drop the mass below 100gr. Changing to a hybrid ogive with the existing tip drops the mass to about 103 gr. If that is acceptable I will prototype it.

      Comment

      • Troutguide
        Warrior
        • Jan 2017
        • 380

        #33
        BFT pardon my ignorance but "weight 96"? thought we were looking for a 105'ish pill?
        "I rarely give a definite answer" - TG

        Comment

        • grayfox
          Chieftain
          • Jan 2017
          • 4295

          #34
          How much case capacity remains when seating this bullet? And given the relative densities of say, cfe223, 8208xbr, and H335 for example, what theoretical load capacities would that be.
          This 105 looks pretty good to me.
          BFT you're driving the boat on this!
          I'll volunteer to help with the testing.
          "Down the floor, out the door, Go Brandon Go!!!!!"

          Comment

          • LRRPF52
            Super Moderator
            • Sep 2014
            • 8569

            #35
            Originally posted by Makerbullets View Post
            I designed this bullet based on the requirements BFT detailed in the thread. I believe I captured all of the input. This is what we can do in a tipped expanding solid copper. I suspect the real world BC to be slightly higher based on other similar designs we have done. I can do a hybrid ogive as well. I just don't have software to calculate the BC of a hybrid. This should give you expansion close to 750 yds (1600 fps). We have a window of about 800 - 1200fps, depending on a number of factors, that we can shift around in the velocity range. Look it over and give me some ideas what you would want to change. I personally just started playing with the 6.5G, so I am game to do some testing.
            Welcome aboard! Have you looked at rebated boat tails?

            We could also push the OAL a little forward and add it to the COL, maybe 10-20 thousandths, to increase the ogive radius. Every magazine out there will take a 2.270" COL with plenty of clearance.

            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

            • BluntForceTrauma
              Administrator
              • Feb 2011
              • 3897

              #36
              Originally posted by Troutguide View Post
              BFT pardon my ignorance but "weight 96"? thought we were looking for a 105'ish pill?
              TG, we're constrained by the shape of the bullet, the form factor. I started the thread talking about lead-core bullets; currently, we're discussing Maker Bullets' capability to make a solid copper projectile with a polymer tip like a Barnes TTSX. For any given form factor, a lead core bullet (lead density is 11.36 g/cm2) will be heavier than an all-copper bullet (density 8.96, depending on alloy).

              I'm willing to design the form factor to get the optimum shape for highest BC within the constraint of a bullet 1.25" long and let the weight fall where it may, which in this case just happened to be 96gr. We want to constrain the bullet length so it doesn't take up too much powder space when loaded to magazine length.

              The beauty of solid copper projectiles is that they don't break apart like a lead-core, so you can go lighter and still have the main mass of the bullet hold together to penetrate.

              The beauty of a high BC solid copper projectile is that the sleek nose allows it to retain velocity so impact speed is higher. Bottom line: Hits harder.

              LRRPF52 makes a good point that we can design a bullet with a slightly longer nose because almost all mags today allow a COL of 2.270 at the least and, more probably, up to 2.300.

              LR1955, makes a good point that nose length has a tipping point — literally! — and if your nose is too long (relative to the rest of the bullet) your bullet will fly with less stability, bleeding BC, and even tumbling and keyholing in the target in a worst-case scenario.

              Every bullet design parameter has to come together in perfect harmony.
              :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

              :: I Drank the Water :: Revelation 21:6 ::

              Comment

              • HONDO
                Bloodstained
                • Jan 2015
                • 34

                #37
                I love this forum...
                Galatians 2:20-21

                Comment

                • BluntForceTrauma
                  Administrator
                  • Feb 2011
                  • 3897

                  #38
                  OK, next. Let's talk solid copper bullets with big tips vs. small tips.

                  My theory with big tips (same theory as Winchester's new Deer XP bullets) is that with a big tip your bullet is already well on its way to max expansion, and at lower velocities.

                  Further, a big tip causes the nose cavity to expand less. "What!?! I thought we wanted max expansion!" Bear with me; let me explain.

                  When a bullet mushrooms, it takes on the shape of a round-nosed bullet. A larger round-nosed bullet than we started with, yes, but a round-nose (RN) nonetheless. When a RN passes through tissue (and this is from Duncan MacPherson's studies in his book Bullet Penetration) it crushes a certain amount of tissue directly in its path but around the rounded edges the tissue sort of "slides" by. Following me? When a wadcutter or sharp-edged cylinder passes through tissue, it crushes the tissue in its path but also cuts, or "cores" it, thereby displacing and destroying more tissue. Further, a bullet creates a shockwave in air and in tissue on impact, and a sharp-edged cylinder shape creates a more powerful shockwave upon impact.

                  Now, the amount of mushroom in a bullet depends on velocity. The more velocity, the more the petals peel back, but they keep basically the same expanded diameter whether the peel back a little or peel back a lot (see photo). The beauty of them peeling back a little is that if the petals STAND OUT 90 DEGREES from the bullet axis, they have the same diameter or caliber as fully peeled back petals, but now they have sharp cutting edges AND the bullet shape is now basically a SHARP-EDGED cylinder with its bigger shockwave. Win, win, and WIN. (See attached photo.)

                  So, I'm gonna advocate for a big tip with FIVE thick petals that expand about 90 degrees from the axis. Let's call it: Five-Finger Death Punch.
                  Attached Files
                  :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

                  :: I Drank the Water :: Revelation 21:6 ::

                  Comment

                  • Troutguide
                    Warrior
                    • Jan 2017
                    • 380

                    #39
                    Thanks BFT. Thats why I asked, learning as I go. I still worry that there is a point of diminishing returns for a hunting projectile as the weight goes down. I know speed trumps mass but only to a point and then sheer size comes into play I would think. I know you all are not just looking at hunting, but I am. So if Maker and Y'all think a 96 or 103 will open long range, hold together close range , and give me two holes wherever then go for it.

                    Not trying to get in the way of the mission here as I know you are going for the perfect form Grendel bullet just throwing my $0.02 wish list out there from the peanut gallery.

                    BFT posted while I was typing and I like what he said. Goes along with my thinking about sheer size and bullet holding together. Sub 100 makes me nervous but that bullet going through would be baaaadddd.
                    Last edited by Troutguide; 12-11-2017, 05:44 PM.
                    "I rarely give a definite answer" - TG

                    Comment

                    • Makerbullets
                      Unwashed
                      • Mar 2017
                      • 6

                      #40
                      Originally posted by BluntForceTrauma View Post
                      OK, next. Let's talk solid copper bullets with big tips vs. small tips.

                      My theory with big tips (same theory as Winchester's new Deer XP bullets) is that with a big tip your bullet is already well on its way to max expansion, and at lower velocities.

                      Further, a big tip causes the nose cavity to expand less. "What!?! I thought we wanted max expansion!" Bear with me; let me explain.

                      When a bullet mushrooms, it takes on the shape of a round-nosed bullet. A larger round-nosed bullet than we started with, yes, but a round-nose (RN) nonetheless. When a RN passes through tissue (and this is from Duncan MacPherson's studies in his book Bullet Penetration) it crushes a certain amount of tissue directly in its path but around the rounded edges the tissue sort of "slides" by. Following me? When a wadcutter or sharp-edged cylinder passes through tissue, it crushes the tissue in its path but also cuts, or "cores" it, thereby displacing and destroying more tissue. Further, a bullet creates a shockwave in air and in tissue on impact, and a sharp-edged cylinder shape creates a more powerful shockwave upon impact.

                      Now, the amount of mushroom in a bullet depends on velocity. The more velocity, the more the petals peel back, but they keep basically the same expanded diameter whether the peel back a little or peel back a lot (see photo). The beauty of them peeling back a little is that if the petals STAND OUT 90 DEGREES from the bullet axis, they have the same diameter or caliber as fully peeled back petals, but now they have sharp cutting edges AND the bullet shape is now basically a SHARP-EDGED cylinder with its bigger shockwave. Win, win, and WIN. (See attached photo.)

                      So, I'm gonna advocate for a big tip with FIVE thick petals that expand about 90 degrees from the axis. Let's call it: Five-Finger Death Punch.
                      Here is what I suggest. I don't know if and when someone who does lead will jump on this, so I will move forward with the solid copper alternative. I am confident that it will work and meet your needs. If not, at least we tried. Since a bigger tip will require a new injection molding tool and a not so insignificant amount of capital, I would like to proceed with the tip I already have and see how it performs.

                      I agree with BFT's logic, but think I can achieve what you want with 3 stiff petals rather than 5 slightly weaker ones. Long story, but we have gone thru this with another OEM where we make them 4 and 5 petal designs, and the results are not what you would expect. They actually bend easier and tend to roll up and then fold back on themselves. On the bigger tip, since the plastic is even less dense than the copper, we give up even more mass. Thus the smaller tip we currently use.

                      We have found that our 3 petal design creates a very sharp cutting surface that tends to flatten out wider than other bullets at high velocity due to the strength of fewer petals and then still stick out at 90 degrees as the velocity drops. We will still move forward with the bigger tip, and we can always make more slits. We currently make over 500 different projectiles from .177 pellets to 50 BMG and everything in between. With the exception of Lehigh, Cutting Edge and Warner, we make a significant number of OEM projectiles that do not always carry our name.

                      I am confident that I can make these and will send samples to BFT for his testing and approval. I should have samples ready within the next 2 weeks. We will begin testing this week on our end.

                      Comment

                      • Randy99CL
                        Warrior
                        • Oct 2017
                        • 562

                        #41
                        Originally posted by BluntForceTrauma View Post
                        I'm thinking there are incremental performance gains to be had by having new, sleeker ogives than the currently available 107/108 and 120/123 bullets.

                        Given the 65G's limited case capacity, am trying to balance lighter weight for velocity with sleekness for BC. Have tentatively settled on 115 grains, splitting difference between 107 and 123.

                        Are there custom bullet makers out there who will make a given bullet design?
                        I'm getting into casting my own lead bullets and found that most available .264 molds are 140g+. I want a bullet around 100-110g and thankfully there are companies that will make a custom mold to any design...the problem is finding a good design.
                        "In any war, political or battlefield; truth is the first casualty."

                        Trump has never had a wife he didn't cheat on.

                        Comment

                        • grayfox
                          Chieftain
                          • Jan 2017
                          • 4295

                          #42
                          BFT:
                          ...Now, the amount of mushroom in a bullet depends on velocity. The more velocity, the more the petals peel back, but they keep basically the same expanded diameter whether the peel back a little or peel back a lot (see photo).
                          I'm reading what BFT wrote, and for the record I don't have any personal experience in this, just learn from what's already out there. In the Grendel Handbook vol 2 (p. 49) it seems to suggest otherwise for the 100 gr ttsx, ie, at higher velocities there is more expansion, up to 2x more than the lowest in the table and rather linear with velocity. Plus, I'm thinking that Barnes et al may have some good reasons for the tip sizes they chose...
                          Just my thoughts of course...
                          For economy sake what MakerB says, makes some sense...
                          "Down the floor, out the door, Go Brandon Go!!!!!"

                          Comment

                          • LR1955
                            Super Moderator
                            • Mar 2011
                            • 3355

                            #43
                            Originally posted by Randy99CL View Post
                            I'm getting into casting my own lead bullets and found that most available .264 molds are 140g+. I want a bullet around 100-110g and thankfully there are companies that will make a custom mold to any design...the problem is finding a good design.
                            Randy:

                            A .264 diameter round ball weighs around 30 grains. A 100 grain, 6.5mm cast bullet would be around 3/4 inch, be a flat base, and have about a 4 ogive.

                            That's why the 6.5 mm molds you see are in the 140 plus grain weights.

                            LR55

                            Comment

                            • BluntForceTrauma
                              Administrator
                              • Feb 2011
                              • 3897

                              #44
                              Originally posted by grayfox View Post
                              it seems to suggest otherwise for the 100 gr ttsx, ie, at higher velocities there is more expansion, up to 2x more than the lowest in the table and rather linear with velocity.
                              GF, your example is true, and I was generalizing a bit and not referring to the absolute extreme examples of the tip just barely starting to "blossom." I guess my point is about the value of having sharp cutting edges on the mushroom.
                              :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

                              :: I Drank the Water :: Revelation 21:6 ::

                              Comment

                              • BluntForceTrauma
                                Administrator
                                • Feb 2011
                                • 3897

                                #45
                                Paul, at Maker, it is excellent to have your knowledge and experienced input. We look forward to seeing what you come up with!

                                RickOShay can do gel tests and maybe some hog hunters can also test on live game.
                                :: 6.5 GRENDEL Deer and Targets :: 6mmARC Targets and Varmints and Deer :: 22 ARC Varmints and Targets

                                :: I Drank the Water :: Revelation 21:6 ::

                                Comment

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