300 RUM/220 SMK gurus. Need your input.

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by Michael Eichele, Dec 20, 2008.

  1. Michael Eichele

    Michael Eichele Well-Known Member

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    How fast have you safely driven the 220 SMK out of your 300 RUM? I was out today toying with the 220's and accuracy was very promising. Was using 90.0 of H50BMG @ an average of 2942 with a 9 FPS extreeme spread. There were no pressure signs whatsover, in fact the primer looked like it was mild. Before I decide to add anymore powder, I was wondering about what is the max velocity for this bullet in this case.

    Shooting 11.25x and 28"

    Thanks!
     
  2. Lightvarmint

    Lightvarmint Guest

    Hello,

    Based on the information that I got from Joel Russo, that may be a little mild. We are anticipating 3200 fps with the 210 grain bullets with a BC north of .900 that I am testing.

    Lightvarmint
     
    Last edited by a moderator: Dec 20, 2008

  3. Michael Eichele

    Michael Eichele Well-Known Member

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    I can tell you that shooting the 200 ACCUBONDS at 3200+ is starting to cause pressure signs. I am pretty sure I wont be getting 3200 with a 210 or 220.
     
  4. Lightvarmint

    Lightvarmint Guest


    What is the bearing surface length comparison of the bullets you are using? Additionally, I have heard that Retumbo works well in the 300SMK.

    Lightvarmnt
     
  5. Michael Eichele

    Michael Eichele Well-Known Member

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    With all due respect LV, I am not trying to calculate how to get to a certain velocity. I am looking for real world experiances and maximum velocities. Not neccesarily with a given powder. So if you have any experiance with this particular cartridge AND bullet combo, I would love to entertain it.

    As far as RETUMBO, I am getting 2940+ with 90 grains of H50BMG with room left in the case for about 5 grains. This is a retorical question. What kind of pressure do you think RETUMBO would generate in my rifle with a 220 SMK? I have pressure problems with RETUMBO in my rig with 180's as it is and TONS of room left in the case. Thanks but no thanks. 338 bores are bigger with more burn area slowing powder down. My tight chamber, tight bore 300 is not very well adapted to RETUMBO.
     
  6. Lightvarmint

    Lightvarmint Guest

    Just curious, what type of action are you shooting? How far off the lands is the bullet for your loads in the 220s?

    Lightvarmint
     
    Last edited by a moderator: Dec 21, 2008
  7. Michael Eichele

    Michael Eichele Well-Known Member

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    Remington 700, 220's are 0.000" off the lands.