7mm WSM Fail Safe

Discussion in 'Reloading' started by alaska, Jul 9, 2010.

  1. alaska

    alaska Well-Known Member

    Feb 1, 2010
    I am trying to duplicate the Winchester factory load in the 7mm WSM with 160gr Fail Safe.

    I need the COL length and the powder charge in the 7mm WSM fail Safe load?

    Thanks for any help

    Jeff in Alaska

  2. J E Custom

    J E Custom Well-Known Member

    Jul 29, 2004

    Hello Jeff.

    It won't do you any good because the powder charge is propitiatory and appears to be
    highly compressed.

    I pulled the bullet on one, and had to dig the powder out with an awl and after I did I
    weighed it and found no load data that could use that much powder even with a few
    grains less (Because the loading books are conservative).

    so I just started using the best powder for velocity and found that the factory velocity was
    not possible unless you want to load over max pressures.

    I found that H4831 sc works well and a few other powders as well and the accuracy improved
    even though the velocity was almost 40 ft/sec slower.


  3. alaska

    alaska Well-Known Member

    Feb 1, 2010
    Did you get the COL? on the 7mm WSM FS with 160gr FS?

    I am trying to dupicate the load in the 7mm WSM.

    The 300 WSM is 69.0 of W760 with the 180 FS.
  4. ForneyRider

    ForneyRider Well-Known Member

    Jan 6, 2010
    I just matched the Win factory ammo for 270 WSM 130gr Nosler Ballistic Silvertips using IMR 4350 and R19. I hit 3250fps, which is what the rifle shot them, no problem and stayed under max load in Lyman data. IMR 4350 did the best. With R19, the velocity went way up with .5gr over max load. But the IMR 4350 load was consistent 30fps with .5gr above or below max.

    I did work up from way below max, as different load data has different max/min etc. E.g. Nosler had 65gr as max load for R22, Alliant 66gr and Lyman having 68gr as max. Nosler also had the highest velocities in their data. Lyman data had 64.5gr as min. R22 wasn't getting it, and R17 was popular for WSM, so I thought 4350 and R19 would do better than R22 and I had them in stock.

    You can take a caliper up to a friendly store and measure the factory ones. However, I bought a box, at $48.50, and shot them up.

    I've read that Winchester uses WLR primers for all their WSM ammo. I used CCI 250 primers. Most of the load data I have uses LRM-type primers.

    Reloading WSM required different powder funnel.