No announcement yet.

M V of 45-70

  • Filter
  • Time
  • Show
Clear All
new posts

  • M V of 45-70

    Hi Guys, if you load up a 45-70 with 70gr 3f black powder 500gr lead bullet what muzzle velocity would you be getting with a 27" barrel. My loading manual has only nitro loads for the 45-70 and trying to set the sights for black powder 200m steel . If I can get a idea of the M V with black I can duplicate it with nitro, 3031 . Thanks guys, pic`s of the beast, Homebrew.357.
    While there`s bullets in the air, there`s hope!

  • #2
    There may be some useful info here -
    -Remote locations are cheap insurance.
    -There are two kinds of ships: Submarines and targets


    • #3
      You are looking at a ballparking of 1100fps I believe.


      • #4
        Thanks guys, that gives me a starting point,
        While there`s bullets in the air, there`s hope!


        • #5
          Some deeper digging into 45-70 says the 45-70-405 standard, was just under 1400fps from a Trapdoor.

          Thus I think the 1100'ish I posted I divined from Hodgdon BP substitute data should be pretty close to the 45-70-500 norm.

          The way their data read, that was the velocity from The Holy Black, and the velocity from the substitute loaded from the same volume (NOT the same weight) substitute.


          • #6
            I shoot a 545 grain cast bullet with 70 grains of cartridge grade GOEX. I have a lab radar, my muzzle velocity is 1200 to 1234 with a 34 inch barrel Sharps. The powder is compressed with the vegetable wad on top and my bullets are not crimped there hand seated. Hope this helps.


            • #7
              Randy has the best answer. I have chronographed my very similar load from a 32" barrel Hiwall. 550 Gr bullet. Very close.
              The whole aim of practical politics is to keep the populace alarmed (and clamorous to be led to safety) by menacing it with an endless series of hobgoblins, all of them imaginary.

              H.L. Menken

              NRA Endowment
              US Navy Retired


              • #8
                I shoot a 512 grn Govt style RN bullet using 23 to 25 grns of SR4759.
                By shooting this bullet at 2 distances I was able to approximate the velocity by comparing it to the trajectory data of the Hornady 500 grn FMJ.

                The 1st edition of the Hornady manual has trajectory table for each bullet at 100 fps increments. You just compare your trajectory to the Hornady tables.

                My velocity turned out to be estimated at between 1200 and 1300 fps.

                I also estimated my cross wind velocity at about walking speed or 4 miles per hour. This corresponded to a wind drift at 100 meters of about 1 inch. One inch is about the wind drift I measured. A group was shot in calm air. Then I fired several rounds when the breeze picked up. These rounds impacted about 1 inch to the left.

                This method requires bullets that are same weight and same ballistic coefficient to be accurate.
                Last edited by ireload2; 12-14-2018, 04:04.