What is a "ladder test"

[jimlj]

I have seen something to the affect of "do a ladder test" when working up a load for a boolit. I didn't want to hi-jack the thread, so can someone tell me what a ladder test is and how to go about doing it?

[TaylorS]

I maybe wrong but If I’m trying to get the most out of one particular bullet and powder I find the MV load I want and do about 10 rounds and depending on max load and cartridge space add or subtract .1-.5 gr of powder until I get 10 set of 10 shoot mark for chrono and acc and go from there. If you wanna tweak it again tighten tolerances on your powder and center around the best from the last round.


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[nicholst55]

Here's an article that explains it pretty well:

http://precisionrifleblog.com/2012/07/13/creighton-audette-ladder-testing/

[osteodoc08]

Take your powder and bullet and appropriate load range.

Load up in .1-.2gr increments across this range.

Shoot at distance such as 100 yards for rifles or 25-50 yards pistol and see which loads cluster together. This is where the barrel harmonics will be the most neutral.

Load up 5-10 shot strings at those loads that shot well together to find the most accurate load.

[toallmy]

This weekend I set out to try a new powder with my Boolit of choice . The Lyman cast bullet handbook # 4 load recommendations were starting load 14.5 - max load of 19. This is a large spread so I loaded a few to shoot groups with at 1. Gr increments 5 rounds of each testing at 100 yards . The results on target showed me wear this particular powder + bullet combination group the best , so now I will load a smaller incremental ladder of probably 2 tenths of a grain around the best charge above and below to see if it helps tighten the group's . Normally a jacket bullet load doesn't have such a large spread between starting load - max load so you do it in smaller incremental changes , and you should always stop your ladder before actually reaching the max load , if you find that your best groups are at the top end of the load you have tried slowly work your way to the maximum charge watching for pressure signs . I hope I didn't make this confusing wile trying to explain it . Some different color magic markers are quite useful when testing charges - I mark each group with a different color marker on the same target and it really shows the size of the group's getting smaller or larger .

[Bohica793]

I have a spreadsheet I put together where I input the max load for the round and bullet combination and it spits out the ladder loads including 3 sighters and 7 actual test loads. I load 3 of each of the test loads and shoot at 100 yards watching not only for groupings, but patterns across the groups. I will then take the best of the bunch and start adjusting OAL to tighten further,

[wendyj]

My husband and I shoot a lot of long range out past 500 yards and up to 1400. We started with the .03 grain increment. Bottle neck and more powder. Quit that due to price of good bullets. We usually start a few grains among minimum and load ten each jumping 1 grain increments. Say we find 42 grains of imr 4350 is giving tightest groups we go back and do .03 grains lower and higher until we see any pressure signs. Once we find that 42.4 grains just an example is the best load we start seating a few thousands deeper and a few thousands longer. Always in strings of 10 bullets. Plan on going a grain or so difference and trying again if you work up in 80 degree and go back out in 20 degree weather. I've never seen any powder that won't shift poi slightly or a lot with extreme temp changes. Seems like a lot of work but it's not bad and well worth the effort. Let barrels cool down between shots. Take a 22 or something to plink while letting barrel cool down. Lower and tighter powder spreads on hand gun calibers might prove a necessity to do .01-.03 powder increments. That's just how we do it. May be wrong but it's worked for my husband to stay sub moa at 1400 and myself at a 1000. Good rest to shoot off of and don't drink caffeine beforehand. Jitters you aren't even aware of.

[Love Life]

I start at 300 yards and load the whole load spectrum from min- max in 10% increments. I’ll refine from there at 400 yards with another test. Save bullets this way, and get more info quicker. I find the nodes and work those. You’ll usually have a high and low node.

[chutestrate]

Take a powder you want and bullets you want to use. Load 5-10 at different increments, say 1.0 grain apart. Keep each separate, and shoot each group of 5 at the same yardage. Mark your shots on another target while you are sitting at your bench. Do this with the entire group of loads. You're looking for the group/s that consistently group close together on the target. Eliminate the shotgun patterns, and work with smallest groups. Load another set of 5-10 in smaller increments .1, .2 grain increments, and see which loads group the best. Process of elimination.

[bangerjim]

If you fall off the ladder, you are too drunk to drive..............or shoot a gun!!!!! :lol:

[gwpercle]

If you fall off the ladder, you are too drunk to drive..............or shoot a gun!!!!! :lol:

LIKE !
We still need a like button

[Shuz]

OK, I've held off no longer.....A real ladder test occurs when the ladder capacity label reads 250lbs max, and [smilie=1:a somewhat portly 280lb man like me climbs on it, and it doesn't break!

[jimlj]

OK, I've held off no longer.....A real ladder test occurs when the ladder capacity label reads 250lbs max, and [smilie=1:a somewhat portly 280lb man like me climbs on it, and it doesn't break!

Thanks for clarifying what a true ladder test is.

Also thanks for the reply's explaining how one might apply a ladder test to shooting.

[trapper9260]

For me when I do a test load of a boolit. what I do is look at the data and see what powders that they have listed and see what ones I have and then for the start load they have. I load 5 of each of the powders I have and then see what one will group the closest and then I work on that one or 2 powders and see what one is the best and then fine tune that one I see will work the best in that one gun.