Are 7wsm &7mm mag data virtually interchangeable??

Discussion in 'Reloading' started by kraky, Nov 11, 2006.

  1. kraky

    kraky Well-Known Member

    Messages:
    301
    Joined:
    Sep 4, 2001
    Posted 11 November 2006 21:09
    Are any of you guys activeley reloading the 7wsm. I went to Hodgdon, nosler, and Imr website and the data seems prety mild. Then I cranked up my quickload program and noticed that it's saying the case capacity is within .5 grain between the two cartridges. (Unlike the 300wsm and the 300 win mag where about 9 grains difference exists) Quickload predicts virtually the same results between the two cartridges and says we can go considerably more powder than the websites I checked.
    The little experiementing I did do was with 56 grains of H4350 under a 154 hornady in my friends 7wsm. It did a whopping 2675fps out of a 24" barrel which is exactly what quickload said it would do. AND...it was exactly what my hornady manual said a 7mm mag would do with the same load.
    Can any of you guys give me some chronographed loads (even factory) loads so I can start cross referencing some info on this cartridge??
    By the way for what it's worth that load was extremely accurate in my friends BAR. 154 hornadys and 160 accubonds went to the same point of impact with the hornadys getting a .7" group and the accubonds at 1". This was a BIG improvement over the win pp factory ammo he had which was doing 2" at 100. (we didn't get to chrono that stuff).
    After hunting season we'll try and work up....its a little embarassing getting 7mm-08 performance out of my reloads when I'm supposed to be 1.5 grains under max according to the manuals.
     
  2. jameslovesjammie

    jameslovesjammie Well-Known Member

    Messages:
    63
    Joined:
    Jun 5, 2005
    According to the Lee Modern Reloading Second Edition, with a 154 grain bullet and H4350 powder in a 7mm WSM:

    Starting load: 54.0 grains-2775 fps
    Maximum load: 57.7 grains-2920 fps at 62,600 PSI

    I don't see in the manual a listing of whether they use a test barrel or an actual one, but I would imagine test.

    According to the 5th Edition Sierra Manual, they don't list a 150 grain load with H4350, but they DO list it for their 160 grain bullet. They go all the way up to 3000 fps with 61.5 grains, and this was shot out of a 24" M70 with WLRM primers. This was also their pick for a hunting load.

    As I'm sure you know...always back off from a max load before starting, but I am pretty sure you could even work up a bit hotter load than you already have and be alright.
     

  3. Aussie

    Aussie Well-Known Member

    Messages:
    250
    Joined:
    Apr 29, 2004
    Read somewhere that 7mm Rem. magnum brass can vary up to about 10 grains in internal capacity from one manufacturer to another so be careful .Also may find if loading for a magazine fed factory rifle that the 7mm WSM won't do as well as the Rem. with heavier projectiles due to requirement to seat long projectiles back into the available powder space .
    No flies on a 160gn projectile at 3000 FPS with H4350 but in my experience the 7mm WSM works better with slower burning H4831SC and Reloder 22 . Magpro is worth a look too but no personal experience with it .