Number of shots (groups) fired for Ladder

Discussion in 'Reloading' started by Alan Griffith, Mar 25, 2006.

  1. Alan Griffith

    Alan Griffith Well-Known Member

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    I'm getting ready to do my 2nd ever Ladder test. 1st was not exactly successful. Rifle is a 24 yr old Rem 700 in 30-06 with a Leupold M8 4x (PARALAX involved here). It was a custom job I had put together where the FACTORY barrel was turned down to a tooth-pick slim .550" at the muzzle and then Mag-na-ported. Very well bedded in a fiberglass stock, fully free floated and trigger pulling a very crisp 3-lbs.

    I'm shooting Nosler 180 Ballistic Tips, fully prepped W-W brass (4th firing sized .003" in Forester BR dies), WLR primers and trying Rel 22 and Ramshot Hunter. I've had both H4350 and H4895 give excellent results with groups occasionally running sub MOA. But, I'm looking for a little more velocity (than the H4895) and consistent accuracy (than the H4350)in the sub MOA department. And, I'm just curious. Isn't that part of the fun of reloading?

    I plan on doing a full blown 300 yd Ladder test. I'm going to start with the Nosler's just touching the lands, seated in Forester Ultra-Seater die. Don't worry, the magazine easily accomodated an OAL of 3.6+" and my current OAL is 3.540".

    I understand the concept of the Ladder and have also used the OCW. I don't have enough experience with either to have a preference. My rifle/scope combo, being an ultralight rig (6 lb 8 oz), is obviously not a heavy barreled F-class or varmit gun, etc., and does not shoot as such. I have read and re-read Glen Zediker's "Handloading for Competition" until it's nearly falling apart. On pages 371-373 he covers the Audette/Ladder Method sufficiently enough that I believe it will work. He even shows a nice diagram of a very successful Ladder (we should all be so lucky to have similar Ladders).

    I'm finally getting to my question!

    Standard Ladder uses 1/one/uno shot per propellant charge increase. Zediker seems to prefer 5-shot groups using the same propellant charge increase. Now, since my rifle is not a target grade, but rather customized "factory", Rem 700, I wanted to get some of your feedback on that. Has anyone used 2-shot, 3-shot, 4-shot or 5-shot groups for the Ladder?

    PS. I reload AT the range "throwing" measured prop charges via my Harrel's Premium Measure.
     
  2. Varmint Hunter

    Varmint Hunter Well-Known Member

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    Just one thought - with a pencil thin barrel it would take you a looong time to do a ladder test if you were using 5 shot groups and allowing the barrel to cool adequately between firings.

    If the barrel was shot cool, warm & hot; I would assume that the fluctuating barrel temperature would influence the results on paper.
     

  3. Alan Griffith

    Alan Griffith Well-Known Member

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    Aug 22, 2005
    VH,

    Agreed! It would take a very long time. Since I'm looking for the faster/higher velocity side of the powder range I had planned on only going down 2 grains from max. This could potentially mean 10-11 groups at a difference of .2 grains per group.

    Big Al
     
  4. Eaglet

    Eaglet Well-Known Member

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    GSSP,
    If I'm understanding the ladder test correctly, the purpose is to find those spots (nodes) where different charges make the least difference, not how each indicidual group of a single charge does, that would defeat the purpose. Once you find those nodes pick the one you like the best, choose the proper charge and now is time to shoot groups of one single charge which you indeed espect to group nicely. Jus my understanding of it. /ubbthreads/images/graemlins/smile.gif
     
  5. D.P.

    D.P. Well-Known Member

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    GSSP
    During ladder testing I would carefully weigh each charge. I use a Harrels also but weigh each and have found it often throws some clunkers. Not sure if you ment throw straight from the Harrels. You want to control as many variables as possible. Also with the NBT's I found all of my rifles liked them .12-.15 thou off the lands. Groups fell apart as I got close to the lands. Not to say yours wont like them at the lands just something I have observed with three .30 cals one Sendero 300 WIn and two custom WSM's. The 180 is an awsome bullet and will often give target accuracy. Good luck hope to see your results.
     
  6. Chawlston

    Chawlston Guest

    Hello,

    You can also do a ladder test by having a fixed pwder charge and then adjust the seating depth in .005" increments to locate the boundaries of the barrel nodes. I find that with premium barrels and good equipment that this works the best for me. In other words.......

    Set up your seating die to seat the bullets just kissing the lands. Next start out with a conservative powder charge. Increase powder volume at an increment you feel comfortable with and go until you some pressure signs and then back off one or two grains.

    Next take that fixed powder charge from above and load a bunch of them up and take them to the range. Shoot two shot groups at each seating depth by just seating the already loaded ammo deeper into the cases and you will be able to locate what load is best for you with the least amount of effort. Using this method, every load I select as the best at 100 yards ALWAYS is the best all the way out to 1000 yards on my private range. Good Luck.

    James
     
  7. abinok

    abinok Writers Guild

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    Its all the same man. Some shoot multiples of an individual charge weight as a double check against their position, and the wind, as well as to get a better feel of ES. The penalty of course is more shots, more expense, and more time at the range. Oh, and lets not forget that you will probably have to clean somewhere in the middle of this thing... another variable to work with.
    My suggestion, if I were in your position, would be to shoot a traditional ladder, doing everything as you normally would, and see how it goes. Either you will have results or not... but whay you will have for a fact is the pressure ceiling for your combo. This way you will know what velocities you are looking at, and at what chargeweights. Then, if you were still unclear about the ladder, you could try your multi-shot ladder with the upper half or 1/3 of the pressure window in order to reduce shots down the barrel that would yield velocities lower than what you are after.

    Just remember that in addition to looking at your group sizes, you are focusing on the location of the group center in relation to the other group centers. Mr Zedikers book dosen't really verbalize it well, but if you look at the graphic, its kinda obvious... if you know what youre looking for.

    Make sense?
    Theres always more than one way to skin a cat... even with something like the ladder test.