Velocity question?s

Discussion in 'Reloading' started by darrindlh, Jul 15, 2011.

  1. darrindlh

    darrindlh Well-Known Member

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    Am i expecting to much out of my 300 wm to try for 2800 fps with a 230grn.

    Darrin
     
  2. Broz

    Broz Well-Known Member

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    I can't say for sure as I have never loaded 230's. But I feel you should be able to get there. It will depend on the rifle as all are different, but my sons 300 wm is sending 210 Bergers at just over 2900 and my 300wm is at 3000 with 210's. Both rifles have 28" Broughtons with 5C rifling and we are using Lapua brass and H-1000 powder. Neither rifle shows any sign of over pressure.

    Hope this helps.

    Jeff
     

  3. darrindlh

    darrindlh Well-Known Member

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    The reason i ask is the new mrk240 rounds are loaded with the sierra matchking 220grn and has a velocity of 2830fps. Don't know about the 230 grn berger how it will fly.
     
  4. Trickymissfit

    Trickymissfit Well-Known Member

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    that's close if not a max load in the manuals (older ones mostly), and I think a lot it it depends on how the throat was cut. If it's a typical .300 Win mag throat I doubt it because you'll loose case volume with the bullet seated down into the shoulder. A .300 Weatherby would do it, and maybe a .308 Norma if it has a the long throat. The Winchester case seems best suited for 200 grain and lighter bullets with the shorter neck length
    gary
     
  5. ken snyder

    ken snyder Well-Known Member

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    Sounds like a not so good of a goal. 230 gr bullet, 2800 fps definately is not a goal for a standard 300 WM. Use a larger case, and a twist rate that will support that long of a bullet.
     
  6. darrindlh

    darrindlh Well-Known Member

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    My overall length is 3.6. I seat the bergers supper long. My intention is not to reach 2800. 2700 fps is more like it. Like mentioned the gov is loading 220 's at 2800. 2700fps prob, i think this would arrive like a hammer

    Darrin
     
  7. Trickymissfit

    Trickymissfit Well-Known Member

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    I'd love to see their load data, as I think they must be running with 70K psi
    gary
     
  8. darrindlh

    darrindlh Well-Known Member

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    Tricky pm me and i will send you the article and the reaserch how they choose the 220's

    Darrin
     
  9. darrindlh

    darrindlh Well-Known Member

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    Tricky pm me your email address and i will email you the article and the reaserch how they choose the 220's

    Darrin
     
  10. Trickymissfit

    Trickymissfit Well-Known Member

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    I'll get you one out this weekend. Reason I kinda wonder is that they show it in the twenty+ year old manuals, but things change in the last ten years or so.
    gary
     
  11. darrindlh

    darrindlh Well-Known Member

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    I here ya. I was looking at my nosler number four and 68 grns of reloader22 yeilds 2757. And that is not pushin it at all. Retumbo and h1000 are not even on there.

    Darrin
     
  12. darrindlh

    darrindlh Well-Known Member

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    I just got off hogdons website and there loading data. 81 grns of retumbo yeilds 2810fps. This is looking good!

    Darrin
     
  13. Trickymissfit

    Trickymissfit Well-Known Member

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    my #26 Hogdons manual shows 77 grains of H1000 with a 225 grain bullet at 2880 fps using a 26" barrel. The the new Hornaday manual shows 70 grains of Magpro with a 220 grain bullet at 2650fps with a 25" barrel. I'd just about imagine that the .300 case would handle 72 grains of Magpro, and would be a very dense load leading to better accuracey. That powder was developed just for big overbore magnum rounds like the WSM family.
    gary
     
  14. diriel

    diriel Well-Known Member

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    This is the information straight from the Neco.navy.mil PDF document:

    https://www.neco.navy.mil/upload/N00164/N0016409RJN30000209RJN30_0002_att.pdf

    "" 3.
    REQUIREMENTS
    3.1 Classification of characteristics. Where critical or major
    characteristic requirements are listed in this specification, they
    are annotated by a “C” or “M” and sequential reference number
    starting with “1” for critical and “101” for major. The letter and
    number are contained in parentheses. The main verbiage of the
    requirement is then surrounded by brackets, “[ ]”. Minor
    characteristic requirements contain no annotation. Reference DOD-
    STD-2101.
    3.1.1 Critical characteristic. One that analysis indicates is
    likely, if defective, to create or increase a hazard to human
    safety or to result in failure of a weapon system or major system
    to perform a required mission.
    3.1.2 Major characteristic. One that analysis indicates is not
    critical but is likely, if defective, to result in failure of an
    end item to perform a required mission.
    3.1.3 Minor characteristic. One that analysis indicates is
    significant to product quality but is not likely, if defective, to
    impair the mission performance of the item.
    3.2 First Article. When specified in the solicitation (see 6.2g),
    a sample shall be subjected to First Article inspection in
    accordance with 4.2.
    3.3 Government-loaned property. Government-loaned property (see
    6.2e and 6.4) might be used for performing tests as specified in
    Section 4 and Appendices A, B and C of this specification.
    Government-loaned property shall be described in the contract where
    applicable.
    3.4 Components. MK 248 MOD 1 cartridge components are the
    projectile, the cartridge case, the propellant, and the primer.
    3.4.1
    Projectile.
    The projectile for the MK 248 MOD 1 shall be
    4
    DS/JXNN/C08/1604A
    the 220 grain Sierra MatchKing® Hollow Point Boat Tail (HPBT)
    bullet, commercial part number 2240, manufactured by Sierra
    Bullets, (Drawing 53711-8330251). The bullet shall have a lead or
    lead alloy core and copper or copper alloy jacket. The bullet
    shall have a nominal weight of 220 grains, with a tolerance of ±0.5
    grains. The bullet diameter shall be 0.3086-0.0005 inches. The
    bullet shall be of the reverse drawn, Open Tip Match (OTM) type
    capable of meeting the accuracy requirements as specified in
    paragraph 3.6.4.
    3.4.2 Cartridge case. The cartridge case shall be .300 Winchester
    Magnum constructed of copper alloy in accordance with ASTM B19, and
    shall not be plated. The cartridge case shall meet the external
    dimensional requirements of ANSI/SAAMI Z299.4-1992. (C1) [A vent
    hole shall be present in the primer pocket of the cartridge case].
    3.4.2.1 Headstamp. The cartridge case headstamp marking shall
    consist of the identification code of the manufacturer, last 2
    digits of year of manufacture and the notation “300 WM” or “300 WIN
    MAG” in accordance with drawing 53711-8330252.
    3.4.3 Primer. The primer shall be a large match rifle primer,
    non-corrosive, nickel-plated, boxer type, and shall be of lead-
    styphnate type. The primer shall have a brass anvil and brass cup.
    The primer shall be capable of meeting the ballistic requirements
    herein.
    3.4.4 Propellant. (C2) [Each cartridge shall contain Hodgdon
    H1000 propellant.] The propellant loaded in this cartridge shall
    contain flash reduction additives or coatings, and shall meet the
    temperature stability and ballistic requirements detailed in
    Section 3.6.
    3.5
    Complete cartridge.
    3.5.1 Cartridge assembly. The cartridge assembly shall be
    manufactured and inspected in accordance with drawing 53711-
    8330252.
    3.5.2 Primer seating depth. The primer shall be seated in the
    cartridge case to a depth of (M101) [0.000 to 0.008 inch below the
    face of the cartridge case head.] The primer shall not be staked
    or crimped in place.
    3.5.3 Cartridge overall length. (M102) [The nominal overall
    length of the assembled cartridge shall be 3.500 inches maximum,
    3.450 inches minimum] in accordance with drawing 53711-8330252.
    The distance from the cartridge case head to the 0.300 inch
    diameter datum on the projectile ogive shall be controlled to
    within ± 0.010 inches. The nominal overall length and the distance
    5
    DS/JXNN/C08/1604A
    from the cartridge case head to the 0.300 inch diameter datum on
    the projectile ogive of the assembled cartridge shall be
    established, within the above limits, by the manufacturer to meet
    performance requirements.
    3.5.4 Cartridge headspace. (M103) [The cartridge headspace shall
    be 0.212 inches minimum, 0.220 inches maximum], in accordance with
    drawing 53711-8330252. Cartridge headspace shall be measured from
    the base of the cartridge case to the opposite surface of the belt
    of the cartridge case.
    3.5.5 Primed case sensitivity. Primed Case Sensitivity tests
    shall be conducted on empty primed cases in accordance with 4.5.5.
    Primed case sensitivity shall be as follows:
    a. b.
    3.6
    (C3) [The mean critical height minus two standard
    deviations ( H -2σ) shall be 3.0 inches minimum.]
    (M104) [The mean critical height plus four standard
    deviations ( H +4σ) shall be 22.0 inches maximum.]
    Cartridge ballistic performance.
    3.6.1 Velocity. (M105) [The corrected average muzzle velocity of
    the cartridges conditioned at 70° ± 5° Fahrenheit (F) shall be
    2,850 ± 50 ft/sec. feet per second (fps)]. The standard deviation
    of the corrected muzzle velocity at 70° ± 5° F shall not exceed 15
    fps. This test shall be conducted in accordance with paragraph
    4.5.6.
    3.6.2 Chamber Pressure. (M106) [The corrected average chamber
    pressure shall not exceed 68,100 pounds per square inch (psi) at
    70°F.] Neither the chamber pressure of an individual sample test
    cartridge nor the average chamber pressure plus three standard
    deviations of chamber pressure shall exceed 78,900 psi. This test
    shall be conducted in accordance with paragraph 4.5.7.
    3.6.3 Operational Temperature Stability (High and Low). The
    velocity and pressure of sample cartridges conditioned and fired at
    the temperature extremes specified below shall be in accordance
    with 3.6.3.1 and 3.6.3.2.
    a. Conditioned at 165°F - 5°F for not less than 2 hours
    immediately prior to firing.
    b. Conditioned at -20°F + 5°F for not less than 2 hours
    immediately prior to firing.
    6
    DS/JXNN/C08/1604A
    3.6.3.1 Velocity. (M107) [The average corrected muzzle velocity
    of the sample cartridges conditioned at -20°F shall not vary by
    more than 75 fps from the average corrected muzzle velocity of the
    sample cartridges conditioned at 165°F.]
    3.6.3.2 Chamber Pressure. (M108) [The average corrected chamber
    pressure of the sample cartridges conditioned at -20°F and 165°F
    shall not exceed 71,500 psi.] Neither the chamber pressure of an
    individual sample test cartridge nor the average chamber pressure
    plus three standard deviations of chamber pressure shall exceed
    78,900 psi.
    3.6.4
    Accuracy.
    3.6.4.1 300 yard accuracy. (M109) [The extreme spread of any
    individual 10-shot group shall not exceed 4.5 inches at 300 yards.
    The average extreme spread of ten, 10-shot groups shall not exceed
    3.5 inches at 300 yards.]
    3.6.4.2 600 yard accuracy. (M110) [The extreme spread of any
    individual 10-shot group shall not exceed 9.0 inches at 600 yards.
    The average extreme spread of ten, 10-shot groups shall not exceed
    7.0 inches at 600 yards.] This test shall be conducted in
    accordance with 4.5.8 and Appendix B, except that the range to
    target shall be 600 + 1 yard. This test shall be conducted as part
    of the First Article Sample or if a First Article Sample is not
    part of the contract, as part of the first production lot of a new
    contract.
    3.6.5 Function and Casualty. (M111) [There shall be no weapon
    stoppages due to the cartridge.] The cartridge shall meet all
    function and safety requirements of Table I. Misfires shall be
    considered separately in accordance with Table I. Function and
    causality testing shall be conducted using the rifles as specified
    in the contract.
    ""

    Please read and note that 68K psi +- a good bit is what they are running and their COAL is like 3.5".... it is all there... read and enjoy.


    Have fun,
    Gary