Chrono data during ladder test

[CharlieNC]

Mike,
The way this stuff was introduced to me is that ladders are just increment tests’ your the only person I know of that says they have to be just one shot.
We do them with one , two or even three shots per increment, we shoot them in a vertical foremat or a horizontal foremat or with colored bullets at one point of aim at a 1000 yards.
We can even do seating ladders that way.
Can you expand on why it’s so important to call out only a one shot ladder a true ladder and why it matters so much?
Thx
Jim

One shot was the " Saterlee" method proposed five or so years ago. His premise was the Chrono is more accurate than group size as a response. But totally ignored poi approach.

 

[dcali]

There seems to be a lot of confusion about what a ladder test actually is. A ladder is a way of finding the velocity that minimizes dispersion due to the motion of the barrel and timing of the bullet launch.

A ladder is a chart of vertical impact point vs velocity. It will have a stair step shape (hence "ladder"). The flats of the stairs are your nodes. You want to pick a velocity in the middle of one of the steps. To do that you need to know what the charge weight should be. You don't need a huge number of shots for this - just enough to see that step pattern. The steps tend to be about 50ish fps wide in my experience, so plan accordingly.

That's why you also plot charge weight vs velocity (this can be with the same shots that you used for the ladder). This is NOT a ladder. There is no name for this. It will be a straight line, and it will NOT have repeatable flat spots. Looking for flat spots and assuming they are good loads is called the Saterlee method, and it's bunk. It does not have any basis in reality.

Try this at long range with an overkill number of shots - like 50. That will end any notion that velocity flat spots exist, and it will show you some good charge weights to explore.

 

[Orr89rocz]

“A ladder is a chart of vertical impact point vs velocity. It will have a stair step shape (hence "ladder"). the flats of the stairs are your nodes. You want to pick a velocity in the middle of one of the steps. To do that you need to know what the charge weight should be”

All the ones i seen posted here is vertical impact vs charge weight. Sometimes velocity is also added.

Interesting thread, always good to read different methods and opinions. Ive done mostly 100 yard testing across my magnetospeed and it’s worked well for me. Charge weight vs velocity indeed looks “flatter” across certain grain weight increment bands and often times that ends up being the best load weight for me. I dont get hung up on technical terms or what you call it. I do the seating after i find that and usually get something i like.

Even with some thin barrel guns ive done group testing with, ive gotten good groups with the magnetospeed on and taken it off to verify and still gotten groups. Sometimes minor poi shifts but overall not terrible. But I guess some guns just shoot better than others and not seem to care

 

[CharlieNC]

As Damon noted, there is no strict definition of a ladder test because the term has been used in various contexts over the years. And various approaches work.

 

[dcali]

All the ones i seen posted here is vertical impact vs charge weight. Sometimes velocity is also added.

That's doable, but it's the half-assed way of doing it. You will get much cleaner data if you use velocity, because that's what the bullet ultimately cares about.

 

[762plinker]

Mike,
The way this stuff was introduced to me is that ladders are just increment tests’ your the only person I know of that says they have to be just one shot.
We do them with one , two or even three shots per increment, we shoot them in a vertical foremat or a horizontal foremat or with colored bullets at one point of aim at a 1000 yards.
We can even do seating ladders that way.
Can you expand on why it’s so important to call out only a one shot ladder a true ladder and why it matters so much?
Thx
Jim

do some real research on ladder testing...probably in the 50's maybe eaarlier. high power shooters, 20 shot string...waybefore recent screwed up terminology and nonladders. simple question, when you go to lowes and ask to buy a LADDER how many have THREE STEPS at each level...none. some one screwed this a few years back and everyone jumped on that band wagon. i have nothing wron with shooting groups for load development, just do not call it a ladder..IT AINT
Precision Shooting "RELOADING GUIDE" (1995) page 91 discusses the ladder with Creighton Audette. this predates most of what you read today, one audette was NOT a benchrest shooter, so that blows a whole in one guys claim this cannot be used for anything else.
this is a simple tool to narrow the search. it is the first step it is not the end...save time and money.
if you can afford to shoot groups to find this data be my guest..JUST DO NOT CALL IT A LADDER.

 

[Ned Ludd]

do some real research on ladder testing...probably in the 50's maybe eaarlier. high power shooters, 20 shot string...waybefore recent screwed up terminology and nonladders. simple question, when you go to lowes and ask to buy a LADDER how many have THREE STEPS at each level...none. some one screwed this a few years back and everyone jumped on that band wagon. i have nothing wron with shooting groups for load development, just do not call it a ladder..IT AINT

Of course it is. It's ludicrous to claim otherwise. I guess you must also believe that Lowes won't sell anyone three different ladders at the same time. I can assure you they will.

 

[Webster]

That's doable, but it's the half-assed way of doing it. You will get much cleaner data if you use velocity, because that's what the bullet ultimately cares about.

Vertical going up with increased load ignores barrel harmonics. I seldom shoot past 300 yards so group size is all that matters.