Testing NEW 6.5mm Cerberus 90 Bullet

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  • Drift
    Warrior
    • Nov 2014
    • 509

    #31
    I love that velocity in a hunting bullet. The accuracy... not so much. Hopefully, these bullets will be the perfect mate to the upcoming Howa bolt action.

    Comment

    • bwaites
      Moderator
      • Mar 2011
      • 4445

      #32
      My early results from the Howa are not happy, more shotgun than rifle groups. I used 30 and 31 grain XBR loads.





      Unfortunately, I'm not ready to declare if it's the rifle or the bullet. More testing is needed, but I have limited bullets!

      Comment

      • BluntForceTrauma
        Administrator
        • Feb 2011
        • 3897

        #33
        We'll tweak that li'l sumbitch as necessary. Next run — due in just days — is gonna be the brass version, Cerberus 85CZ, so it'll be a whole 'nuther experience, yet again.

        Ric, middle bands on C90 are each 0.020 wide, with the rearmost band abutting the boat tail being 0.075. Design is grooves cut into bearing surface like a Barnes, as opposed to a driving band "bore rider" design.
        :: 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

        • ricsmall
          Warrior
          • Sep 2014
          • 987

          #34
          Bill

          Maybe I missed a post in other thread but have you shot a series of groups with a known accurate load? I know you stay on top of these things just wondering if you had anything to compare it to.

          ETA: I measured a Barnes 120 TSX and the relief grooves and remaining bands look to all be .069". I don't know if that's something to consider, just throwing it out there. They've done years of research and it may help John as well as everyone else reach their goal a bit quicker.

          Richard
          Last edited by ricsmall; 02-28-2016, 04:02 AM.
          Member since 2011, data lost in last hack attack

          Comment

          • bwaites
            Moderator
            • Mar 2011
            • 4445

            #35
            Ric, like this?



            Yeah, it shot some pretty fair groups. It did seem to like heavier vs lighter. I haven't written up Thursday's range session because I had a couple interesting and unexpected things happen and I'm hoping for some additional information.

            Comment

            • BluntForceTrauma
              Administrator
              • Feb 2011
              • 3897

              #36
              Guys, need some brainstorming to improve accuracy of these Cerberus bullets. I'm wracking my brain, asking myself, "What could possibly go wrong?" There are many possibilities.

              1. Are copper bodies machined concentric?
              2. Are aluminum tips machined concentric?
              3. Is nose cavity drilled on center?
              4. Is tip seated on center?
              5. Is tip knocked off center as is rams up the feedramps and slams to a stop in the chamber?
              6. Does bullet like chamber?
              7. Does chamber like bullet?
              8. Is there an optimal seating depth?
              9. Is there an optimal — oh, what's the term — front-to-back weight distribution of the material in the bullet?
              10. Are the bullets consistent with each other, that is, exact clones?

              I ask myself, "Is it problematic that it's a two-piece bullet?" But, then again, other tipped bullets are two-piece, and if they have a lead core, a copper jacket, and a polymer tip, they're three-piece!

              Need some theories here, no matter how wild, to help diagnose this. What can be done to improve accuracy?
              :: 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

              • cory
                Chieftain
                • Jun 2012
                • 2985

                #37
                Originally posted by BluntForceTrauma View Post
                We'll tweak that li'l sumbitch as necessary. Next run — due in just days — is gonna be the brass version, Cerberus 85CZ, so it'll be a whole 'nuther experience, yet again.

                Ric, middle bands on C90 are each 0.020 wide, with the rearmost band abutting the boat tail being 0.075. Design is grooves cut into bearing surface like a Barnes, as opposed to a driving band "bore rider" design.
                Are they already doing the 2nd run? If possible I'd have them hold up as some tweaks are looking like they may be necessary. Any idea how far forward the aluminum tip has pushed your CG?
                "Those who sacrifice liberty for security, deserve neither." Benjamin Franklin

                Comment

                • BluntForceTrauma
                  Administrator
                  • Feb 2011
                  • 3897

                  #38
                  Holding off on the second run of copper. Going forward with the first run of brass. Have mechanized tip-seating method for the brass version, so should be more consistent.

                  Don't know about the Center of Gravity. I'm lacking technical expertise. Looking at the market, I see CGs all over the place. Lapua's 6.5 100 Scenar, for example, is literally half lead, half empty nose cavity. I know the Cerberus design is more well-balanced than that, with a slight weight bias toward the rear like almost all target bullets.

                  If we can get the kinks worked out, it's quite possible from a 16-inch barrel we could have a 0.450 BC bullet in copper going 2900 fps and a 0.420 brass version going 2950 fps. I'd feel really good about that.

                  But we need less than 1 MOA, for sure, and if we got 0.5 to 0.75 MOA from standard reloading I'd be happy to call it done.
                  :: 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

                  • bwaites
                    Moderator
                    • Mar 2011
                    • 4445

                    #39
                    I will be loading some for a trial in an AR next go around. The fact that I had a couple touching makes me believe there is hope.

                    Comment

                    • xlcc
                      Warrior
                      • Feb 2016
                      • 210

                      #40
                      I think you would be lucky to get those bullets to shoot perfect on your first attempt.A little adjusting of the bands of width and or depth may be required too.How close are the weights of your test bullets?Keep it going,you are on the right track.By changeing from copper to brass construction you are throwing in another variable.

                      Comment

                      • stanc
                        Banned
                        • Apr 2011
                        • 3430

                        #41
                        Originally posted by BluntForceTrauma View Post
                        Guys, need some brainstorming to improve accuracy of these Cerberus bullets. I'm wracking my brain, asking myself, "What could possibly go wrong?" There are many possibilities.

                        1. Are copper bodies machined concentric?
                        2. Are aluminum tips machined concentric?
                        3. Is nose cavity drilled on center?
                        4. Is tip seated on center?
                        5. Is tip knocked off center as is rams up the feedramps and slams to a stop in the chamber?
                        6. Does bullet like chamber?
                        7. Does chamber like bullet?
                        8. Is there an optimal seating depth?
                        9. Is there an optimal — oh, what's the term — front-to-back weight distribution of the material in the bullet?
                        10. Are the bullets consistent with each other, that is, exact clones?
                        Items 1-4 and 10: Haven't these been checked by the bullet maker? Do you have the ability to measure them?

                        Item 5: Is there any way to check this?

                        Items 6-7: Seems impossible to determine at this stage.

                        Item 8: Quite possibly.

                        Item 9: You mean, is there an optimal Center of Gravity? That seems possible, too. Might require testing many different variations to find out, though.

                        I ask myself, "Is it problematic that it's a two-piece bullet?" But, then again, other tipped bullets are two-piece, and if they have a lead core, a copper jacket, and a polymer tip, they're three-piece!
                        True. Question is, how many iterations did those manufacturers have to develop in order to work out all of the kinks?

                        Need some theories here, no matter how wild, to help diagnose this. What can be done to improve accuracy?
                        1. Get the answers to your items 1-10, and resolve any problems discovered. Retest.

                        2. If accuracy problems persist, alter bullet design. Produce new batch. Test. Repeat as necessary.



                        ETA: The Cerberus looks like it was made by being turned on a lathe. http://www.65grendel.com/forum/showt...l=1#post126924

                        Perhaps that manufacturing method can induce slight variations in weight, shape, concentricity?

                        In contrast, Barnes punches the TSX and TTSX into the desired shape from sized copper slugs.

                        - https://www.youtube.com/watch?v=aiw5EkqxnQQ
                        - https://www.youtube.com/watch?v=GCgr8JOde-A
                        Last edited by stanc; 02-28-2016, 11:26 PM.

                        Comment

                        • Bill Alexander
                          Bloodstained
                          • Jul 2015
                          • 35

                          #42
                          Remove the tips and shoot the shank alone. Removes a whole set of variables.

                          If the shank shoots then the tip is moving the CofG axially in which case the bullet does not stabilize or you have good old fashioned eccentricity.

                          If the shank does not shoot then the engagement with the rifling or the base if the bullet is not behaving.

                          Comment

                          • BluntForceTrauma
                            Administrator
                            • Feb 2011
                            • 3897

                            #43
                            Thanks, Bill. Of course! Doh!
                            :: 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

                            • rickOshay
                              Warrior
                              • Apr 2012
                              • 784

                              #44
                              Here is my input on the 90 g Cereberus

                              All my work was with my 18" Lilja. Max COAL for this chamber is 2.273 for 123 AMAX and 2.250 for 123 SST.

                              Loads were done with H335 because of my previous experience with down-loading for gels, and all the methods were the same as given in Chapter 6 of the 6.5 Grendel Reloading Handbook Vol 2.

                              I was a bit conservative on loads because 31 grains of H335 fills the Grendel case to the neck, and the C90s seat significantly into the case. All loads only had one shot due to supply of bullets. The usual disclaimers about load data apply. Start lower than these listed and work up, looking for signs of pressure on primers and case heads.

                              Hornady brass and REM 7.5 primers. Loaded to 1.667 ogive. It was 76 F today at the range.

                              28.5 g - 2673
                              29.0 g - 2759
                              29.5 g - 2777
                              30.0 g - 2793
                              30.5 g - 2855

                              There were no ejector marks or flattening of primers. Probably could go a bit higher as PA_Allen did.

                              Now for the gels. I loaded down to give approximately 2250-2300 fps which would be equivalent to what the bullet would be doing at about 300 yards.


                              First shot was the C90 without tip. It fragmented on impact and the core exited the top of the second gel. My apologies for the bubbles in the gel. The dispersion of fragments was about 3 inches. in diameter and penetrated about 3-4 inches.

                              Looking at the side of the gel. Bullet entered from right.


                              The second shot was the C90 with a tip. The tip delayed opening to about 7 inches of penetration. Dispersion was limited to about 1.5 inches. The core exited the top of the second gel.

                              Looking at the top of the gel. Bullet entered from the bottom.


                              Now Sneaky had drilled out the hollow core of the C90s to end up with what I will call S83s

                              Shot without tip dramatically opened at impact with a fragment dispersion of about 6" and frag penetration of about the same. The core travelled 34" and was recovered. Pic below.

                              Looking at the top of the gel. Bullet entered from the bottom


                              And finally, an S83 with tip reacted the same. Tip delayed opening to about 7". The tip can be seen in the photo below at about 8.75" facing backward. The core traveled 32" and was recovered. pic below.




                              There are more fragments created by these bullets than the Controlled Chaos, and they are opening up more at low velocities. see http://www.65grendel.com/forum/showt...l=1#post125242

                              Sneaky's modifications did help in opening up the C90.
                              Last edited by rickOshay; 02-29-2016, 03:44 AM. Reason: brass and primer info

                              Comment

                              • rickOshay
                                Warrior
                                • Apr 2012
                                • 784

                                #45
                                Here are the pics of the recovered cores:

                                The S83 without tip after 34" of penetration. The front measures 0.295 - 0.299. Basically a .30 cal wad cutter.



                                And here is the S83 with tip recovered after 32" of penetration.


                                Group photo
                                Last edited by rickOshay; 02-29-2016, 02:25 AM.

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