Cast bullets labeled 180gr. TC .358" but weigh 170gr. Load for....?

Discussion in 'Ammunition & Reloading' started by dgang, Oct 6, 2019.

  1. dgang

    dgang Member

    Uncovered a stash of NBC cast bullets from years ago. They are labeled .358" 180gr. TC but weigh 170. gr. Would a high alloy mix account for 10 gr. of weight? Do I load for 180gr. or 170gr.? Planning on using 13 gr. of 2400. Sound right?
    Thanks in advance, dgang
    Last edited: Oct 6, 2019
  2. OldManMontgomery

    OldManMontgomery Active Member

    .358 Winchester, .35 Whelen, .35 Remington and lever guns chambered for .357 Magnum all have .358" diameter bores. And .357 Magnum revolvers, of course. From the load you mention, I assume the latter.

    The Lyman #50 book had loading information for a 170 grain cast lead bullet in .357 Magnum. If the bullets weight 170 grains, I would use that information. (Why the discrepancy? Could be mislabeled; I don't know.) My book has a start load of 9.7 grains and a maximum load of 13.5 grains; using 2400 powder.

    Sounds to me like your proposed 13 grains would be too close to the top for me as a starting load.

  3. SGWGunsmith

    SGWGunsmith Well-Known Member Supporter

    A high "tin" content used in the casting mix could also account for the lighter actual weight of those bullets.
    Rifling82 likes this.
  4. dgang

    dgang Member

    I think that the bullets were mislabeled, it would take a lot of alloy to make a 10 gr. difference in a 180 gr. bullet.
    I did load them at 13 gr. of 2400, made for a nice solid load with no signs of over pressure. Will put them through my Chrony when the weather breaks., expect about 1175 - 1200 fps with my 4" barrel. Thanks to all and good shooting'.
    Last edited: Nov 14, 2019
  5. crossfire

    crossfire Member

    Measure the seating depth and load for whichever weight bullet it's closest to.