257-65-FN (Bob’s Boat tail)

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  • 2015-10-13 at 15:28 #488311
    SwedeNelson
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      Working with rsterne (Bob’s Boat tails) on some Air rifle moulds
      We have come up with the following design
      14″ Twist


      Post if you have any interest and will see what we can do.

      Bullet maker, maker
      Al Nelson

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    • 2015-10-13 at 21:39 #500729
      rsterne
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        We plan to increase the diameter of the drive band by 0.002″ on all molds but leave the nose diameter the same…. This should allow sizing without issue…. The nose will center in the bore as it engages the rifling fully and we don’t want to increase the friction by having it larger than necessary…. I understand that Al can make the diameter of the molds to suit your needs within reason anyway….

        Bob

        2015-10-19 at 04:44 #500730
        rsterne
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          I think this would make a very destructive little Hollowpoint as well…. Al?….

          Bob

          2015-10-19 at 12:50 #500731
          SwedeNelson
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            To work with our RG moulds the meplate would have to be enlarged to .20
            Then it could be done.

            Bullet maker, maker
            Al Nelson

            2015-10-19 at 15:47 #500732
            rsterne
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              Hmmmmmmm…. that’s pretty big on a .257, nearing 80%…. Tough call…. Now I understand what your criteria is, though….

              Bob

              2015-11-23 at 07:47 #500733
              teemu
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                I’m in

                2015-11-23 at 16:33 #500734
                rsterne
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                  Me too, with a Lyman style HP pin in one cavity….

                  Bob

                  2016-06-15 at 08:13 #500735
                  tnt76
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                    I’d like to add my name to the list to get this one closer to reality.
                    Thanks

                    2016-07-25 at 14:17 #500736
                    rsterne
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                      This design has been moved to a Group Buy….  http://noebulletmolds.com/smf/index.php/topic,1632.0.html

                      Bob

                      2017-01-22 at 18:53 #500737
                      rsterne
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                        If you are interested in this bullet with a slightly smaller diameter, to fit .25 cal airgun barrels, please post here…. I am proposing that it be made available in 0.250/0.252″ or in 0.253/0.255″ just like the 41 gr. and 51 gr. BBTs were…. Let’s see if there is any interest, please…. I think it should work in the 15.5″ twist Green Mountain MRod barrel up to 800-900 fps, maybe a bit more…. In the .250 cal, it would be about 60 gr. for the FN, or 57 gr. for the HP version, and about 62 gr. FN  / 59 gr. HP for the .253 cal…. 

                        Bob

                        2017-01-29 at 15:13 #500738
                        Christopher
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                          Bob,

                          Interested in the .250 diameter bullet. If you shot the 60 grain bullet @ 950 fps in a 14″ twist barrel I certainly wouldn’t think it would be much trouble to shoot the 51 grain bullets 950-1000+.  Would the 51 gr/48gr. HP stabilize at those speeds with a 14″ twist barrel (i.e. the same gun)? Obviously, a little detuning would be in order when going from 60 gr to 51 grain.

                          Thanks,
                          Chris

                          2017-01-29 at 17:04 #500739
                          rsterne
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                            Yes, the 51 gr. should be fine in a 14″ at 1000 fps….

                            Bob

                            2017-06-15 at 06:32 #500740
                            tnt76
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                              My best group with the 65 BBT, this one in HP form.
                              1st shot was high, 2nd low and 3 and 4 were back high with the 1st. 2nd shot flyer??
                              Tight group measured .13 ctc. Hope to get out and do some follow up groups.
                              946fps. 100yd

                              2017-06-15 at 15:29 #500741
                              rsterne
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                                Wow, that sure shows some potential…. just have to figure out that flyer?….

                                Bob

                                2017-06-15 at 21:38 #500742
                                tnt76
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                                  Yes, shows potential.  As mentioned, this is my best group (excluding flyer) usual groups are 1-1.5″ ctc, but mainly with the solid version.  Maybe the cg being a little further back helps?  Rifle is sighted in for the Arsenal 71gr 257420 BT, which goups ok too, which is why the POI is high.

                                  Next casting run of 65 BBT, I will be a little more thorough with quality control and also sort them.  I was having a little trouble maintaining a sharp trailing edge on the rear band, so maybe the flyer was one of those that slipped through to the tin.

                                  2017-06-15 at 22:16 #500743
                                  rsterne
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                                    Still, 1-1.5″ C-T-C at 100 yards is nothing to be ashamed of….  8)

                                    Bob

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