7mm rem mag ladder test?

Discussion in 'Reloading' started by jrw1976, May 30, 2010.

  1. jrw1976

    jrw1976 Well-Known Member

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    I am going to start working up a load for my 7mm rem mag and I was wondering if you guys could give me an idea of what the max load should be in my ladder test. I will be using 154 gr interbonds and h1000. All my reloading manuals have slightly different max loads and I keep reading on here that the 7mm likes a hotter load and that published max loads are on the light side. I am just looking for a ball park figure to work back from and then methodicly shoot up to in my ladder test, to see what the old girl likes. Thanks JRW
     
  2. MN Hunter

    MN Hunter Well-Known Member

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    I normally start in the middle of the range and work my way up to published max load. I then load past that in 1/2 grain increments up to 3 grains over. More often than not I don't get that far and end up taking rounds apart but it saves me a trip to the range. I have found that often the loads that shoot best end up around 2 grains short of max. I have had guns that the final load I settled on were above max. However my 338 rum started showing pressure signs 1 grain below what Barnes listed in their manual. Take your time to work your way up.
     

  3. jrw1976

    jrw1976 Well-Known Member

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    Thanks I just wanted to get an idea of what the majority was finding as an actuall max load range in the real world not a computer genirated max. I am also wondering what you guys are using for a medium range bullet for ranges of 150 to 600 yards. I am really looking at the hornady 154 gr interbond for this purpose am I on the right track with this choice. The reason I am leaning this way and not jumping on the berger band wagon, is because I tend to be an opportunist hunter. If a nice muley buck jumps up inside of 100 yards away I am sure as heck not going to turn around and walk 200 yards away just because I have a long range load in the gun. I want to be able to just pull up shoot with confidance. Thanks JRW
     
  4. ForneyRider

    ForneyRider Well-Known Member

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    For 7mm Mag, I work up from min to max in .5gr increments with R22. I pick a COL that suits the load's purpose and keep with it.

    I had to extrapolate R25 load for 168gr SMK. I maxed out at 68.5gr which was 1/2 way between the 160gr max load and 175gr max loads I had R25 data on. I was 200-300 fps below my expected velocity and accuracy was the worse of any of my 7mm loads. The 68.5gr load was the most accurate of this combination, but since the accuracy was bad, I've decided to go back to R22. The felt recoil of the R25 loads were much heavier than other loads.

    I use LR primers for most of my 7mm mag loads.

    For one load, I am below min on most load data but the load was very accurate. 50gr IMR 4064 and 120gr Nosler BT. I got the load data from Lee book. It was well below other load data.

    Aside: for .223, I go up in .3gr increments. But there is about 2-3gr difference between min and max in most of my load data. It is softer shooting than 7mm mag.
     
  5. flashhole

    flashhole Well-Known Member

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    Nov 15, 2009
    I tried H-1000 but got a lot better results with Retumbo. I shoot 175 grain bullets in my 7mm RM so I'm not much help there. What I will suggest is you do your ladder test at a minimum of 300 yards else you will be wasting components.
     
  6. jrw1976

    jrw1976 Well-Known Member

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    I can only get 250 yards out of the draw in front of my house where I have my shooting bench set up. Do you think that will do? Well it is going to have to because it works out really good only being 100 yards from my reloading room when I am fine tuning a load.