L.R. Rifle Reloads

Discussion in 'Reloading' started by dave1, Jun 3, 2011.

  1. dave1

    dave1 Well-Known Member

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    I have a 7 rum that i have been working up loads for. I am in Central PA. I have a few topics I would like to hear other guys speak about.

    First I'm debating about load development in the summer months compared to winter shooting months. I mostly test loads in the heated summer days. Where I hunt , Snow is on the ground 80% of the time during rifle season. I am up in the air about this? Do other guys take the time out of the winter rifle season to sight in loads? This gun will be a 300 plus yard gun only. nothing really closer then 300. Anyway im dumbfounded with this.

    Second .
    The guys that do shoot l.r. and reload are you using a chrono to test loads? If so at what distance are you testing at? I have read articles about chronos and im undecided?

    I have a round i like as of right now. It was tested in the summer. 100-300 yard test.

    I would love to test loads at 100 and 500 yards in the winter and then get leupold caliber specific knobs.
     
  2. Ridge Runner

    Ridge Runner Well-Known Member

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    I work up to a safe max load in simular conditions to my hunting season, usualy around sept/oct, too much varience in MV in extreme temp. changes



    I chrony at 5 yards, then use ballistic programs to figure my actual MV. The knobs will work pretty well in the east to around 700 yards, beyond that the current atmosperic conditions must be taken into account, you can only do this with a ballistic program, or file full of drop charts.
    Not saying its the only way to do it but its what works best for me.
    RR
     

  3. J E Custom

    J E Custom Well-Known Member

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    Depending on what brand of powder you are using you need to check velocity swings from summer
    to winter.

    Some powders are temperature sensitive and some are not. so testing your load will tell you if you
    have a problem with this.

    During the summer I load down from max and during the winter I can up the powder charge
    if I have to on some powders.WARNING!!! These loads should not be used during the summer
    and should be marked so.

    I chronograph every thing I load at 16' and measure drop out to the distance to be used because
    with temp changes comes other factors that can effect bulled flight.

    The chronograph is a wonderful tool for long range shooters but it will not tell you what your
    bullet is doing at different distances.

    Take/make the time to sight in during the winter. Most serious long range shooters even check
    zeros when changing altitude.

    J E CUSTOM
     
  4. dave1

    dave1 Well-Known Member

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    I will shoot in winter months the first chance i can. What chrono does most guys like? I am debating on buying one.. I have never tested any of my reloads on a chrono.
     
  5. trebark

    trebark Well-Known Member

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    Shooting without a chrono is like shooting with your eyes closed. I use a Chrony Master...

    Shooting Chrony F1 Master Chronograph - MidwayUSA

    My buddy uses a ProChrono...

    Competition Electronics ProChrono Pal Chronograph - MidwayUSA

    We have tested these against an Oehler and have been satisifed that they do not "lie"
     
  6. flashhole

    flashhole Well-Known Member

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    Hodgdon makes an entire line of Extreme powders that are "temperature insensitive". I can vouch for several that their claims are valid. I don't own a RUM but I used to own a 300 Win Mag. I used Retumbo powder with good success and didn't have any pressure problems regardless of air temperature. I suggest taking a serious look at Retumbo. Winchester Large Rifle Magnum primers worked well for me with this powder.
     
  7. dave1

    dave1 Well-Known Member

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    My 7rum seems to love h-50bmg. I also loaded a few with rl25. I would like to find a good load with the h-50. Lyman book says the accuracy load is 104 grns. with a 150 grn swift scirocco. I load that bullet .

    I have been wanting a chrono for a while. I reload a decent amount.

    I was loading them right off the lands but i could only use it as a single shot. Lyman says 3600 for the caol for just about every bullet it lists. I am going to see if i can get a good load trhat will still fit in the mag.

    Any tips or anything i should know be4 using the chrono?
     
  8. jimbires

    jimbires Well-Known Member

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    tip #1 , don't shoot it . LOL sorry had to say it .

    keep it away from the rifle about 10 feet or more , muzzle blast can affect it .

    I put tape about 5 inches up on my wire uprights that hold the sky screens . that gets me the same height above the sensors each time and I can see through the scope if the chrony is level , by looking at the tape on the front and rear uprights .

    I'll piggy back a question on here . what do you do to keep the sun from affecting the velocity readings ? my velocity will make a big change from overcast to sunny sky . I use a chrony beta . Jim
     
  9. trebark

    trebark Well-Known Member

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    Set your target up, then get on your rifle and get it pointed right at the target. Set your chronograph 12' to 15' feet in front of your muzzle. You can adjust it's placement by looking threw your scope or pull the bolt out of your rifle and site it through the bore. Just make sure that the rifle is pointed threw the 'sweet spot' of the chrono (center of the 'v').
     
  10. dave1

    dave1 Well-Known Member

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    I'm looking at some of the units for sale. Anyone own the Competition Electronics ProChrono Digital Chronograph? This seems like a decent unit. I dont think the remote will be a big deal for me.
     
  11. trebark

    trebark Well-Known Member

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    A buddy of mine has the ProChrono - it works just fine. Because it will store data for a string, we have set it out in front of a target at 200 or 300 yards and place another chronograph at 12' from the muzzle. It is interesting to see the actual velocity at 200/300 yards, the ES and whether or not it matches data from ballistic programs. Although I'm not unsure of the equation, but I understand you can use the two velocities to determine true BC of a bullet.
     
  12. Outlaw6.0

    Outlaw6.0 Well-Known Member

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    THAT I didn't know, I would like to read more about that topic, very intriguing.... To the OP, I have the Chrony Master as well, it's been a great unit for me.
     
    Last edited: Jun 9, 2011
  13. rscott5028

    rscott5028 Well-Known Member

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    I'm pretty certain ALL powders are affected by temperature.

    Hodgdon Extreme powders are less affected than most.

    I compared H4831sc vs RL22 for my 7RM in weather ranging from 102F to 32F and H4831sc was far less affected. I don't have my data in front of me. But, I think there was something like a 25 fps drop in the avg mv for H4831sc and RL22 dropped around 150 fps. The std dev or accuracy wasn't really affected though.

    Whether or not you care about a 25 fps or 150 fps difference in MV will depend on how far you shoot.

    As suggested, use a chrony and record your data in summer and winter.

    -- richard
     
  14. dave1

    dave1 Well-Known Member

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    I am going to get a pro chrono I think, It should be intresting to test my loads. Any other guys use that h50-bmg powder?