help w/ 7mm RUM loading

Discussion in 'Reloading' started by ackiddblast, Aug 14, 2005.

  1. ackiddblast

    ackiddblast Active Member

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    Jul 24, 2005
    i am currently reloading 150 gr. scirroco seated at 3.60 and 88.5 gr. of H-1000 and using a 9 1/2 rem. primer. At 100 yards i have been shooting a 0.24 in. group, i moved out to 500 yards and shot in excess of 5" three different times off of a bench giving the barrel plenty of time to cool. Does anyone have any advice i am open for any suggestions.

    kiddblast
     
  2. davewilson

    davewilson Well-Known Member

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    Feb 19, 2004
    try the longer heavier bullets.160 accubonds, 175 sierra's, 168 or 180 bergers.
     

  3. Buffalobob

    Buffalobob Writers Guild

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    Check the parallax setting and or eyepiece focus on your scope.
    Check your bifocals.
    Check mirage.
    Check wind.
    reclean your gun,
    recheck the action screws.
    check the temperature your load was developed under
     
  4. jrdoty

    jrdoty Well-Known Member

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    What type of reloading dies do you use? Sounds like you may have a problem with bullet run-out. Or that particular load my have a high SD. have you checked that load over a cronograph?
     
  5. ackiddblast

    ackiddblast Active Member

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    I'm using RCBS dies and have not shot the load over a chrono yet. I am very new to reloading so you will have to elaborate with the bullet run out, and i cannot understand why this round is doing well at one range and not another. By looking at other recipes i am not shooting to hot a load and the atmospheric conditions are the same little to no wind. My groups are just scattered on the page like i am shooting off-hand.
     
  6. Buffalobob

    Buffalobob Writers Guild

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    I do not know how long you have been shooting and do not wish to be too simple but my first impression would be that you have a stock weld/ paralax problem. That is why I listed those possiblilites first. It is very easy to get 0.5 MOA error with bad stock weld and bad paralax together. You can often get by with one problem or the other but when you have both simultaneously things go down the sewer in a hurry. Many cheap scope are set for paralax at 100yds and when you move out from there the problem becomes severe. If your scope does not have paralax adjsutment, then you msut have a very consistent shooting mechanics to get your eye in the exact same place and alignment each time. Tack this much error onto the wind and mirage effects at 500 and you have your answer. If you already know all of this then I apologize for going on and on and on about it. You should not expect to hold the same MOA at 100 yds all the way to 500yds but you should be doing better than you are.

    Secondly, I would make very sure that the barrel is very clean.

    To follow up on the bullet runout possibility you can do a search of this site for "run out" or "concentricity". Basically it means the loaded cartridge is not in line with the barrel and the bullet starts down the barrel out of alignment. This can be caused by an out of alignment chamber (my problem with one gun) or it can be caused by your reloading process of either bending the brass (usually the neck) or seating the bullet off alignment. Take several loaded cartridges and roll them across the table and see if the tip of the bullet wobbles around. If it wobbles on the table it has "runout" from center.

    If you are new to relaoding there are some common beginner mistakes that will create a problem in excessive runout. First, if you have bottomed out your decapping rod then it is probably bent and will bend all of your case necks when the expander ball comes out of the case. Secondly, if you did not lube the inside of the case necks and the decapping rod is off center it will bend the case necks.

    I will go back to my first suggestion. Next time you go to the range shoot at 100yds and then at 500 yds. If you get good groups at 100 and bad at 500 then this is not a reloading issue, it is a scope/eyeball issue.

    These are jsut my opinions. Take what you want and throw the rest in the garbage.
     
  7. daveosok

    daveosok Guest

    1) What type of rifle is it?
    2) What twist is the barrel?
    3) Have you examined the crown?
    4) Have you examined the lug contact?
    5) When installing the scope did you lapp the rings?
    6) Is the correct torque value used on the action screws?
    <u>7) Is the barrel free floated?</u>
    8) Did you weigh your cases?
    9) Did you weigh your bullets?
    10) Did you measure your bullets diameter and base to ogive?
    11) Have you trimmed the meplat?
    12) Measured the cases for consistancy?
    13) Seated the primer at the right depth?
    The solutions to the problems are numerous as you can see. Everyone on here has gone directly to solutions without knowing first where the problem may lay.
    Answering these questions posted above will give us a better idea of where to start instead of getting overloaded with all sorts of data that may or may not correct the problem.
    Come on fellas lets ask the real questions and give this guy some better answers based off the facts.
    Then you can say its your paralex, bolt lugs, scope rings, crown or whatever may be the problem.
    If you solve all of these issues or if they are not issues then on to the loading aspect of it.
    Some of the easiest solutions could be answered by questions 2, 3, 4, 6, and 7.
    JM2C