Creighton Audette method for developing loads?

Discussion in 'Long Range Hunting & Shooting' started by EXPRESS, Oct 5, 2003.

  1. EXPRESS

    EXPRESS Well-Known Member

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    Just curious, does anyone here know of or use this method for load development?

    I imagine it would be very revealing operating at longer ranges than most shooters confront.

    I would like to try this method to find out what my new rifle "likes" also because I have plenty of time on my hands till I get around to actually shooting it...
     
  2. Brent

    Brent Well-Known Member

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    I use the ladder method also. I do repeat it more than once to confirm the results tho, three times is best. My Father likes to do it with five shots groups at .5gr increments and compare POI changes, but to each his own I guess. I'll post a pic of his target from yesterday when he was testing a load in his new Armalite AR-30 300wm. Nice barrel on it that hardly even fouled too, shot real well ta boot.

    When I get the barrel broke in on this 30-338 LI, I think I'll do my ladder testing at 500 yards this time, although MV will play even a larger role than it would at 300yds, group spread would wider and might help to see distinct clusters in the group even better.

    [ 10-05-2003: Message edited by: Brent ]
     

  3. Gibbs505

    Gibbs505 New Member

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    What is this method, I have never heard of it? [​IMG] [​IMG]
     
  4. Martin@Hin

    Martin@Hin Member

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  5. BountyHunter

    BountyHunter Writers Guild

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    Go to post on this board, 12-24-02 under bullets, barrels and ballistic. Look for Ladder Method.

    Works great but works best at 300-400 yards.
    The intervals and clusters are real easy to distinguish.

    BH
     
  6. EXPRESS

    EXPRESS Well-Known Member

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    for those who have used this method, @ 300m, how much vertical spread should one expect over a 2, 3 or 4 grain of powder span?

    I suppose the best way to go about it would be to have all your shots on one paice of paper, or a long sheet of plyboard, so you could to the shooting in similar conditions over a few days, weather permitting.

    I was thinking of shooting each round with a .1grain difference.
    Not because I think there will be any great difference, just so as to have more shots on paper and to highlight fliers or my own bad shooting and convetrsly, to highlight the groups in the ladder pattern.


    Sound like a good idea?
     
  7. BountyHunter

    BountyHunter Writers Guild

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    I normally go to 400 yards and I us .2 gr increments. My jumps are normally about .75 to little over 1 inch. They will move up and then cluster for 3-5 shots and then move again and then cluster again. Each cluster is a sweet spot for tuning. over 3-4 grain ladder can get 4-5 sweet spots. pick one closest to your desired MV

    Key points are:

    1. clean white poster board target with small aiming dot at bottom. Easier to spot hits.

    2. Must have chrono to plot MV for each shot

    3. Mark each shot on minature target paper at bench as you shoot it. also another sheet to write MVs

    4. Good highpower spotting scope is essential to see bullet holes at 400 with others near it. Must plot each shot individually on your bench sheet, only way to tell which shot is what.

    5. Target will show clusters and when compared to MV records easy to see sweet spots and point of diminishing returns with powder.

    6. take about 5 rounds at lowest powder weight to zero at 400 on another target right next to clean ladder target.

    7. Start at lowest weight and go up.

    8. Method only works with exact components used, ie cannot change bullets or primers in your load after and think it will be same, reshoot ladder.

    BH

    [ 10-06-2003: Message edited by: BountyHunter ]
     
  8. Brent

    Brent Well-Known Member

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    The only thing I can add to what BH said is that the horizontal extreme spread will also be a good indicator when you're not in the zone, you just have to try it to see I guess. Every gun is an individual and you can expect to see any where from .5" to 3.5" spreads between shots, not all of it is from increase in MV, or change in bbl whip. Recoil effects this big and a few other minor things too. Be consistant with bench technique and the results will be most interesting and helpfull. A lot of the vertical spread depends on how well the rifle will shoot the load throughout the range, the more it likes the combo, the tighter the vertical, the worse it likes it, the wider the spread... in most cases.
    I can't find a single pic of a target I've done this with or I'd post them, I know I had some at one point. I'll be sure and get some of the next ones tho.

    Everything BH said about plotting each shot correctly on a target, or drawing of one at the bench is critical. if you can't associate each POI with the charge weight it had in it, it's perfectly meaningless.

    At some point you may have to even go down range after each shot and mark each shot, don't wast your time by keeping on shooting if you aren't sure.

    I fire three or four foulers at the starting load before I ever start the test too. The bbl is let cool so it remains about the same temp for each shot.

    Dan Newberry has a modified way of doing it also, but Dan tends to only shoot near the top end range and a pretty narrow one I might add. As my dad does, he looks for where the POI shifts in the group are. Dan rarely goes to 300 yards with his tests tho, and I believe the ILDM (incremental load development method) as Audette used it is more usefull, in that all the loads increments are grouped together on the same target and there is nothing to figure out to measure the shift etc. 300 yards is minimum for good data IMHO.