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  1. #1
    Senior Member VooDoo's Avatar
    Join Date
    Jun 2014
    Calgary, Alberta

    Optimal Charge Weight Load Development

    Bit of a read but came across this article - has anyone tried this before?

    OCW Instructions
    Warning! It is assumed that you are an experienced handloader
    who follows safe handloading practices. If you have not read and
    understood the basic instructions in a reputable loading manual
    (such as Sierra, Lyman, Speer, Nosler, Lee, or Hornady), please
    DO NOT continue here until you have done so. It is not my intention
    to bring the novice up to speed on case prep, safe bullet seating
    length, and such. There are scores of volumes written on these
    very basic handloading issues, so repeating such instructions here
    would seem redundant.

    1. Decide on the bullet you want to use.

    2. Choose a powder. This is probably the most important step in the
    whole process. As a rule, you should choose the slowest burning
    powder practical. There seem to be plenty of exceptions here, so if
    you have it on good authority that a slightly faster powder works
    well with the bullet/cartridge combo you're using, feel free to choose
    that powder. A couple of examples would be IMR 4350 in the 30-06
    and IMR 3031 in the .243 Winchester. An aside: When in doubt,
    consult the Nosler manual for their "most accurate powder tested."
    That powder nearly always gives good results in the application

    3. Consult at least three load data sources for maximum charge
    weight for the powder you've selected. Powder manufacturers are
    the most reliable source. You must then decide on what your
    maximum charge will be.

    4. Back away from the maximum charge by 5 to 7 percent, and load
    one test round with this charge. Add 2% to the charge weight, and
    load another cartridge with that charge. Load a third test cartridge
    with the next 2% graduation. You will use these three cartridges for
    sighters, and more importantly to determine pressure tolerance in
    your individual rifle. They will also "season" the barrel with the
    powder that you're testing--always a good idea.

    5. Add another 2% or so to the charge level used in cartridge #3 of
    step 4, and load three rounds with this charge weight (you may
    want to load four rounds, in case you pull a flyer, and need an
    extra). Add .7% to 1% to this charge, and load three more. Add that
    same graduation again, and load three more. Continue adding the
    chosen graduation until you have moved ONE increment above
    your chosen maximum powder charge. If I'm working with a .223 in
    the 20 grain powder charge area, I move in .2 grain increments.
    With the .243 and .308, I like to move in .3 grain increments, and
    with the 270 and 30-06 I might use .4 grain increments. The larger
    the cartridge, the larger the graduation.

    6. The seating depth for all test loads should of course be the
    same. I normally seat the bullet a caliber's depth into the case, or to
    magazine length--whichever is shorter. I don't believe loading to
    approach the lands is necessary, or even desirable in most
    situations. So long as the bullets are seated straight, with as little
    runout as possible, the advantages of loading close to the lands are
    largely over-stated. This said, be certain that the seating depth you
    choose does not cram the bullet into the lands. Stay at least .020"
    or so off the lands for these excercises.

    7. The primer brand you choose is entirely up to you. Use magnum
    primers only with magnum chamberings, as their added pressure
    can distort the OCW conclusions on standard chamberings. You
    might choose to try a magnum primer with your load recipe after
    you find the correct charge, as in limited situations a magnum
    primer will tighten your velocity numbers.

    8. At the range, you should set up 5 to 7 targets at 100 yards. The
    number of targets you use will depend on how many "sets" of
    cartridges you loaded. Be sure the targets are identical, and level. I
    like to use a simple black square, drawn on a white background
    with a large felt tip marker. I draw the square about 3/4" (interior
    dimension) for my 9 power scope setting. This allows a "tight fit" of
    the crosshairs in the square, and thus a repeatable sight picture.
    For higher power scopes, draw the square smaller, and vice versa.

    9. You can also put up one "sighter" target, and use the initial
    reduced rounds to get the POI on paper, as close to the bullseye as

    10. Your barrel should of course be clean before starting. Most
    barrels settle in to good accuracy with a controlled amount of
    copper fouling in the bore. (If a barrel won't shoot well fouled, the
    rifle may as well be a muzzle loader, right?) With a decent barrel,
    you will not need to clean during the test, and I don't advise
    cleaning until the test is complete.

    11. After you have fired the sighters and confirmed that there are no
    pressure signs (hard bolt lift, flattened primers, etc.) you allow the
    barrel to cool for an adequate amount of time (use common sense--
    the hotter it is outside, the longer it will need to cool) you will then
    fire your first shot from the first group of the graduated charges. You
    fire this shot at target number 1.

    12. Allow the barrel to cool, then fire a shot from the second
    graduation at target number 2. Wait for cooling of the barrel, then
    fire a shot from the third graduation at target number 3. Continue
    this "round robin" sequence until you have been through all of the
    targets three times. At this point you will have a three shot group on
    each of the targets.

    13. It is assumed that you are an experienced reloader, and that
    you know to watch for pressure signs on each of the increasing
    charges. Fire the subsequent charge only if there are no
    pressure signs on the previous charge. You can safely fire the
    heaviest charge you loaded so long as the next charge under it
    showed no pressure signs. This "heaviest charge" should be about
    1% over your selected maximum charge, but will be safe so long as
    the next lowest graduation showed no pressure signs. It is
    necessary to test this slightly higher charge level since the OCW
    might end up being right on the published maximum.

    14. Triangulate the groups. This means to connect all three shots in
    a triangular form, and determine the center of the group, and plot
    that point on the target. Measure this point's distance and direction
    from the bullseye, and record the information somewhere on the
    target. Do this for all of the targets. If you have a called flyer, you
    should discount that shot, or replace it in the group if you have an
    additional round loaded with that charge (and having a fourth round
    is always a good idea).

    15. You will now look for the three groups which come the closest to
    hitting the same POI (point of impact) on the targets. The trend of
    the groups should be obvious, normally (but not always!) going
    from low and favoring one side, to high and favoring the other side.
    But along the progression, there should be a string of at least three
    groups that all hit the target in the same relative point.

    16. After you have carefully measured group sizes and distances
    and directions from the bullseye, you will know which three groups
    come the closest to hitting the target in the same POI. You now
    choose the powder charge which represents the center of this
    string. For example, if 34.7, 35.0, and 35.3 grains all grouped about
    1.5 inches high, and about 3/4 of an inch right of the bullseye, you
    would choose the 35.0 grain charge as your OCW (optimal charge
    weight). This charge will allow 34.7 and 35.3 grain charges to group
    right with it. This will be a very "pressure tolerant" or "resilient" load.

    17. Remember, don't get "bowled over" by a tiny group which falls
    outside the OCW zone. You can tune any of the groups to be tiny
    with bullet seating depth changes. After you have determined the
    OCW, you may want to try seating the bullets deeper or longer in
    .005" or .010" increments to see where your particular rifle does its
    best. If you're a real stickler for accuracy, you can do another
    "round robin" test using varied seating depths, perhaps in .003"
    increments. Look for at least two seating depth stages that hit the
    same POI and group tight as well. This said, I have often found that
    OCW recipes are so reliable that seating depth alterations--
    especially for game hunting cartridges--often don't seem necessary.

    18. Your next step would be to confirm your load recipe at the
    maximum range you will expect to use it. Load one round about 1%
    below, and another round about 1% above the OCW charge, and
    fire a three shot group with these two charges plus the standard
    charge at the maximum range you will require the load to be
    accurate at. You should note MOA, or very close to MOA

    19. The OCW load development plan works best with rifles and
    shooters that are actually capable of MOA accuracy. If your rifle has
    not shown a propensity for reasonable accuracy, you may want to
    have it corrected before wasting time and material with additional
    load developement. If you are not confident that you are at a level
    where you can shoot consistent MOA groups, you may want to hold
    off on intricate load development until your skills are better honed.
    Lots of practice with a scoped .22 LR is invaluable...

    20. I would sincerely recommend using shooting glasses during the
    firing sequences of ANY load testing. You can never be too careful
    here... And please know that anytime you embark on load
    development, you're basically on your own. Just like any provider of
    load data or development instructions, I must mention that I accept
    no responsibility whatsoever for any occurrences which are outside
    the realm of your expectations...

    * Use brass that is on the same firing, and is still fresh. If the brass
    has been fired more than three times, or if you have a mixture of
    cases which have been fired different numbers of times, you will
    want to anneal your brass.

    * Be sure your brass has been properly and *evenly* trimmed. A
    full length sizing is often the best way to set up the brass for the
    OCW test. This is not to say that neck sizing is a bad idea--it is
    simply to say that you don't want some cases having tight chamber
    fit, and others which others fit normally. This introduces another
    variable that is best eliminated with a full length sizing of the brass.

    * When you're shooting your test, do not load a shell to fire and
    leave it chambered for longer than 10 to 15 seconds. If the barrel
    has warmed up a bit, you'll be "baking" that shell in a hot chamber,
    and potentially alter the burn rate of the powder, skewing your
    results. Chamber the round only when you're within seconds of
    firing it.

    * On multiple occasions, I find that a client in an OCW consulting
    session has loose scope base screws, or loose action screws. We
    figure that out only after he's gone to the range and comes back
    with poor results. It's way more common than you'd think. So it
    would be a good idea to check the torque on all of the scope
    mounting hardware as well as the action screws in the rifle before
    shooting a test.

    * It is a good idea to establish an "accuracy standard" with rifle and
    shooter before endeavoring to develop a good handload. Factory
    ammo is pretty good these days. Spend 20 dollars on a box of
    Federal Fusion, or Hornady American Whitetail, or other reasonably
    priced ammo if you can find it in your rifle's chambering, and see
    how it shoots. If it won't hold 1.5 MOA or better, there could be
    something wrong with the system that needs sorting out before you
    waste time and material attempting to work up a handload.

    * If you are using bushing type neck sizing dies, I would
    recommend .004 thousandths of neck tension. Using only .002
    thousandths in brass that isn't neck turned, or which may be in
    need of annealing normally results in inconsistent neck tension.
    Consistent neck tension is vitally important for accuracy.

    * Be sure to use a target that you can see the aiming points clearly
    on. Tiny scribbled ink blobs from a ball point pen on a cardboard
    box will not cut it (yes, I've seen this). And focus your scope's
    reticle against a neutral background (white wall, blue sky, etc.)
    before using the scope. If your cross-hair gets blurry while you're
    trying to shoot, there is a focus issue either on the reticle or with the
    scope's main focus setting. Know how to use your scope before
    shooting for accuracy! Shadows in the peripheral field of view in
    your scope means you have improper eye relief, and accuracy will
    be ruined. Get the "full moon" sight picture in the scope with proper
    eye position behind the scope. This is very important, as many
    folks do not realize that crescent shadowing in the scope's field of
    view means that you're not really aligned on the target--even if the
    cross-hair itself is on the target. There are two points of reference
    in any sighting system. With iron sights, it's the front and rear
    sight. With a rifle scope, it is the cross-hair, and the straight,
    shadow free path of light making a "full circle" that is the second
    point. Use your scope correctly or you won't be shooting straight.

    * Many times a client in a consulting session finds the load he is
    looking for, and turns in some photos of excellent groups. Weeks
    pass, and I get another email with a horrible group and the client is
    asking "What's wrong?" In 99 percent of cases, he has simply had
    a bad day at the shooting range. The shooter is the most volatile
    part of the entire accuracy equation. If the screws haven't worked
    loose on the scope mount or action, odds are *overwhelming* the
    problem is shooter error, or "loose nut on the trigger" as we say.
    The fastest and most effective way to develop accurate
    handloading recipes for your rifles and handguns.
    Dan Newberry's Optimal Charge Weight Load Development...
    University of Texas at Austin 2014 Commencement Address - Admiral William H. McRaven

  2. #2
    Canadian ForcesMember
    Join Date
    Jul 2014
    Robson Valley, BC
    Good stuff. Thank you.
    Waiting for first light.

  3. #3
    Senior Member
    Join Date
    Sep 2015
    It's literally some guy named Dan Newberry ideas and opinions. Like the "Ladder technique" that doesn't actually tell you anything about how a particular load shoots out of your rifle.
    " will want to anneal your brass..." Annealing has nothing to do with mixed brands or just 3 times or any set number of timesthe case has been fired.

  4. #4
    Member Great White Hunter's Avatar
    Join Date
    Dec 2018
    Hi ,
    Good article, but as Justice said some text is misleading related to "just 3 times". did he mean to say for the very maximum load? And what about the annealing? I dont' know anything about it, if the shell is cracked, I throw it out.

    Thx VooDoo for posting.

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