what is a ladder test??????

Discussion in 'The Basics, Starting Out' started by 30-06 boy, Jan 4, 2006.

  1. 30-06 boy

    30-06 boy Well-Known Member

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    i've seen some posts about"ladder test"what the heck is a ladder test.from what i can tell, it's a accuracy test of some kind???????????may try it if it seems like a good thing.jason
     
  2. royinidaho

    royinidaho Writers Guild

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    its a good thing!

    Do a search on "ladder test" and go back at least a year. Lots of good information and details.
     

  3. ol mike

    ol mike Well-Known Member

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    30-06,

    It's an incremental reloading procedure that you start out loading a minimum load and go up with each round 2-3 or even 5 grains at a time until you reach max load.
    You then fire the rounds at -say 300yds and record each shot ,when you see a group/cluster of rounds land together this is the velocity your gun likes.
    You can then load in smaller increments,say 1-2 grains to fine tune even more.Then start playing with seating depths and such."CHANGE ONE VARIABLE AT A TIME".
    This info comes from varmint safari website ,its a good read and there are may others, but that is the jest of it.Mike
     
  4. abinok

    abinok Writers Guild

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  5. BountyHunter

    BountyHunter Writers Guild

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    It is a proven method to shoot a limited number of bullets (20-30)with a given powder, bullet, primer combo and find sweet spots for that barrel.

    Go to this thread and start for step by step. Ol Mike forgot to put the "." on his numbers. If you go up a whole 2.0 grains at a time you will completely skip a sweet spot. I use .2 or .3 gr intervals over a 3-6 grain spread.


    http://longrangehunting.com/ubbthreads/s...h=true#Post7548

    That thread will link you also back to a 12-24-02 thread on the Audette/ladder method I posted then.

    BH
     
  6. ol mike

    ol mike Well-Known Member

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    I just caught that i didn't use a point [.] as Bountyhunter said, /ubbthreads/images/graemlins/grin.gif that little point is quite important.
    Bountyhunter also gave a truer answer as to what a ladder test 'is'.ME
     
  7. LRHWAL

    LRHWAL Well-Known Member

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  8. Bart B

    Bart B Well-Known Member

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    I, for one, don't think a ladder test is a good thing. Nobody I know of gets the same results shooting the same rifle with the same powder charge increments. And if any test results aren't the same time after time, the test isn't any good. I tried ladder testing years ago and gave up; test results weren't repeatable.

    If someone has got the same results doing the same ladder test three times in a row, then they have my attention.

    A bit of research will show folks that a 1/4th grain change in a .300 Win. Mag. powder charge changes muzzle velocity about 10 fps. A 100 fps muzzle velocity spread causes about 1.5 inches vertical shot stringing at 300 yards. With a 20 fps muzzle velocity spread (pretty good) with a given charge weight, half the shots fired after a 1/4th grain change will leave in the same muzzle velocity range as the previous charge produced.

    Go figure......
     
  9. BountyHunter

    BountyHunter Writers Guild

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    Bart

    I have repeated a ladder and come out with same results. More importantly the results have been repeated in matches with sub moa groups repeatedly at 1000.

    IF you use a chrono with the ladder you can spot the tuning nodes of the barrel and fine tune in the middle of a node.

    Particularily if you use OCW all you know is that you have a similar POI. No way to tell where the pressure jumps and not, just a crapshoot if you hit one in the middle.

    I have seen and repeated a 10-15fps spread for 3-4 shots in a node while I have seen jumps of up to 25 fps with .3 gr in the next bullet out of the node in both 300 Win and 300 WSMs.

    It is not uncommon for LR BR and LR hunting guns using this tecnnique to be well under 20 fps and even under 10.

    w/o chrono is like throwing chicken bones in the air and reading them.

    BH
     
  10. Bart B

    Bart B Well-Known Member

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    Bounty Hunter, now you have my attention.

    Questions....

    What is a node?

    How do you spot the tuning nodes of a barrel using a chronograph?

    Do you think it's possible for several dozen different rifles with different actions and barrel configurations to all shoot the same ammo into sub half-moa groups at 600 yards?
     
  11. Len Backus

    Len Backus Administrator Staff Member

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    BH

    [ QUOTE ]
    like throwing chicken bones in the air and reading them.

    [/ QUOTE ]

    That phrase is clever. /ubbthreads/images/graemlins/smile.gif Is it original? Can I use it?

    PS, I printed your older ladder test post last week and intend to try the method soon. Thanks.
     
  12. BountyHunter

    BountyHunter Writers Guild

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    [ QUOTE ]
    Bounty Hunter, now you have my attention.

    Questions....

    What is a node?

    How do you spot the tuning nodes of a barrel using a chronograph?

    Do you think it's possible for several dozen different rifles with different actions and barrel configurations to all shoot the same ammo into sub half-moa groups at 600 yards?

    [/ QUOTE ]

    A node is where the POI and the fps coincide. My previous post mentioned where the fps jumps shrink say 20 every shot to 3-4 shots going into a 15 fps extreme spread. Go to the next shot and you are back to 20 fps jumps and your bullet jumps POI. You have just discovered a node or sweet spot.

    Shoot a 15-25 bullet ladder at .3gr intervals and can run into 2-4 nodes. Normally about 2-3 where POI and MV coincide.

    Can a certain number of guns shoot the same load into .5 MOA?

    A: You bet. Are we talking that is the best groups ever shot under ideal wind conditions? Does that mean those guns will do that day in day out in match conditions, then no way or they are all owned and shot by David Tubbs.

    Does that mean that load is the best for that gun? Probably not, most people take a load and tweak it to a given point that they are happy with and leave it. The USMC team here at Quantico shoots one load for 600 yards using 90 gr JLKs with one powder and weight. Is it the most accurate load for each rifle no, but it gives acceptable accuracy out of the BR in all guns and they can live with that level.

    Would love to see the equip list where 2 dozen guns on the line list exactly the same OCW load. Doubt you would see that even in the Palma guns where it has to be 308 and 155 bullets.

    Pretty sure you are talking about the magic IMR 4895 load you mentioned earlier. Would almost bet that most that most of them started real near the magic number in ideal testing conditions, shot a couple groups that went .5, they were happy and suddenly the magic load works in every gun and suddenly the magic number is the most accurate load in the world in every gun because if gives .5 moa in a custom action and barreled gun.

    Any LR BR gun with dang near any load will post .5 MOA at 600 in match conditions day in day out.

    Will that win in 600 yd BR even if shot off a rest? No way! Got to be in the .2-.3 MOA arena and OCW will not get you there from what I have seen. Or at least on one has been able to prove it yet.

    BH
     
  13. Bart B

    Bart B Well-Known Member

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    Bountyhunter, I asked "Can a certain number of guns shoot the same load into .5 MOA?"

    Your Answer: You bet. Are we talking that is the best groups ever shot under ideal wind conditions? Does that mean those guns will do that day in day out in match conditions, then no way or they are all owned and shot by David Tubbs......Doubt you would see that even in the Palma guns where it has to be 308 and 155 bullets.

    My followup: This happened in 1991 and 1992 with Palma rifles shooting at 600 yards. Several dozen people from around the world shooting Swing, Barnard, Musgrave, Winchester and Remington actions with Border, Obermeyer, Kreiger and other barrels built by lots of 'smiths (none of which were David Tubb) commented their rifles shot half moa or less at 600 yards with Sierra 155's all with the same load.

    And David Tubb is not the only person who builds and shoots very accurate rifles. In fact one or two people actually do build more accurate ones. But David shoots what he builds very, very well.

    Later you say: "Any LR BR gun with dang near any load will post .5 MOA at 600 in match conditions day in day out. Will that win in 600 yd BR even if shot off a rest? No way! Got to be in the .2-.3 MOA arena and OCW will not get you there from what I have seen. Or at least on one has been able to prove it yet."

    My followup: I know one has to shoot 5 shots into almost an inch to win a 600-yard BR match. But folks have shot Palma rifles at 600 yards with iron sights and put 5 shots into about an inch. I've done that myself slung up in prone. But like 600-yard BR aggregate matches, they're won with about 3-inch group aggs which is what these rifles shoot for 20 consecutive shots. From the 600-yard BR match scores I've seen, individual matches are won with groups about one half to one-third the size of aggregate matches. It's about the same with 1000-yard BR matches.

    Has anybody tested a 600-yard BR rifle to see how accurate it shoots for 20 consecutive shots? I sure like to hear about the results.

    It all boils down to the simple fact that there is no difference between a properly built Palma rifle and 600-yard bench rifle as far as accuracy is concerned. Do some research and you'll learn what some folks have known for years.
     
  14. BountyHunter

    BountyHunter Writers Guild

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    Bart
    YOur response:
    "My followup: This happened in 1991 and 1992 with Palma rifles shooting at 600 yards. Several dozen people from around the world shooting Swing, Barnard, Musgrave, Winchester and Remington actions with Border, Obermeyer, Kreiger and other barrels built by lots of 'smiths (none of which were David Tubb) commented their rifles shot half moa or less at 600 yards with Sierra 155's all with the same load."

    That is really amazing because it does not look it has happened since, but understand that is what they "commented". Seems I have heard several similar comments too (in the bar after 6 beers usually). Sounds like that might be an urban myth unless there is an equip list listing 20 guys all shooting the same OCW load to go with it. Find that list showing that load and you have my attention. Suggest you go to LR target shooting forum where the top Palma and Fclass shooters hang out. Look at their listings of top Palma loads. Only about 2 of the 20+ or more listed Palma loads are even 4895 and they widely differ so they have not discovered the wonders of this load.


    Guess the world teams there have not learned about OCW and the miracle 4895 load.

    "It all boils down to the simple fact that there is no difference between a properly built Palma rifle and 600-yard bench rifle as far as accuracy is concerned. Do some research and you'll learn what some folks have known for years."

    Never said there was a difference in many cases. However, I have seen many Palma rifle come to the line at Quantico at our 1k matches and guess no one knew the miracle load, because they sure did not hang with the BR guns. As far as research, if you are basing the OCW belief on the 1991 miracle load that seems to have been lost to all the top Palma shooters in the last 16 yrs, you might want to do some research too. IF OCW is all you think, then that load would still be valid and top load today.

    I will watch that LR Target shooting board and see how many you convince to go to your OCW 4895 load. Just let us know when you start convincing them. Get em to switch and heck I might try it myself.

    Ah, isn't this fun anyway. /ubbthreads/images/graemlins/laugh.gif

    BH