Home Forums Hunting & Shooting Long Range Hunting Ladder test, How, why?

I am now 100% convinced that ladder testing is as valuable as a proper barrel break-in procedure.

David

Which book? They will routinely show a wide variance for min-max powders and actual pressure test with stain guages show you can have as much as 7000 PSI variance by changing primers. Now add variances of cases, bearing surfaces, throat lengths and you are all over the map. The book data is for standard chambers, throats etc and not custom configurations and wildcats, many of which have no book.

yes, the books are a starting point and that is all.

Umm, the ladder test only shows you a starting point too.

Sometimes a kiss will do
Sometimes you have to run it in
Sometimes you pull it out
It all depends on pressure

That's what she said....

Very good sir!

Not really, the ladder takes your starting points from the book or other sources and runs it up to pressures IF you do it right and then gives you normally two nodes which you can fine tune in. I normally go to book max at the upper end for the upper end of the ladder and a little more to see pressures, but often do not even shoot all of them if I am hitting more pressure signs or hit target MV with a node.

I will normally take the middle of the node at the MV range I want, shoot groups .1 up and down then tune seating depths from the final powder grain selection.

So what you do is run an incremental charge weight test UP until you find pressure, THEN work back down to find your accuracy?

Ok, now you've given us not any more info than boxer and dropped down to posting pictures.

I expect more of you.

While I"m convinced I get further quicker by Audette, instead of just quoting the damn mantra, tell me HOW you get to where you do. STEP by STEP.

Such that myself and others could compare.

Hell we may all be doing the same thing and using differnet words...???

Seriously, find max pressure by chrono? But how do you account for all the variations in ways to get to max speed? Its fairly well known that depending on what routes you take in a given cartridge/firearm, you can hit max pressure at a multitude of speeds.

Once you have found pressure, then what do you do to find the best accurate load once you have a point of no mans land that you won't venture into again.

Which btw I generally find on the fist 10 single rounds out of a barrel.

Certainly while I believe books, I don't think I've EVER had the exact components listed in a book and they rarely delve into twist, number or type of rifling, chamber types etc... much less brand of brass or more rightfully so capacity of brass etc...

You didn't ask for more.

Ive repeatedly ask for more than kiss find pressure rock on. More than once I am 99% sure. Not directly to you, but to other posters that only say ladders are not the best way to go, in words not quite the same.

If ladders ain't it, offer HOW to do it better.

If you'll note, I've done the same on my end, offer how/why I use what I do...

Others, nothing but useless words and waste of time and not helping anyone at all other than having to read through more mumbo jumbo..

Good bless those that were born with the knowledge to do things the best way and perfectly from their birthing day....

The unfortunate part about this thread, is that it has deteriorated to the point that the guy yelling the loudest, and the most, thinks he's right.
If more than two shots are fired, then it's a ladder.
Chronographs are useless and are not to be trusted.
All strings/ladders have to be shot at 600 yards, and ignore wind and environmental influences, even though they contribute to both vertical and horizontal stringing.
Barrels move as much as .001" perfectly vertical, every time the trigger is pulled.
A huge sample is required to get accurate SD numbers.
And of course, Kiss, find pressure, and rock on.

These are just some of gems pulled from this thread. At this point, how, or why, anyone would want to even attempt to contribute is beyond me, as it has become more about being right, than sharing knowledge.

As I said from the start, more than one way to do things, and end up at the same place...

R.

Well ya can always try to save a thread.... I'm stubborn in case you didn't know...

If you didn't have someone telling otehrs theirs is the only way to start with it would be a civil disagreement type discussion....

And the damndest thing, the OP wanted ideas on how to do things, specifically about the Audette, and its been bashed to death. Even though he didn't ask about other methods, had others been civilly cited and actually explained, I think we'd have been a better thread here.

There is one common denominator though about how it got ruined to start with.

Chronographs are not worthless. You aren't concerned with the actual velocity (unless you are getting some unrealistic numbers based on what the cartridge is known for). You are concerned with the deviation in velocity between each identically loaded round fired.

DC223, how do you go about working up your loads?

I don't think I ever said they were, but you like I are probably responding to a different post than mine. Quick reply ya know.

Of course I dont' want to be looking for that deviation until I know where max is and I know where its likely to be the most accurate to start with...

I've asked him repeatedly and can't get an answer

The only person on this thread who has offered an explanation of the methods he uses is Jordan, and even then, no explanation of the KFPRO method can be found.

Here is an explanation step by step.

My methodology is pretty similar after I have done basic research to determine, bullet,primer, and powder combo I want to use/test for each ladder. Now this might be many reloading manuals, others recommended loads, Qload, etc, but I find a "suspected" powder, primer, bullet and case and then work a load that is normally about 2-3 grains below max to 1-2 grains over at .2 to .3 increments depending on case size. Normally this is 15-25 bullets only with 4-5 extra of the lowest charge for initial zero on the other target.

I use the smaller increments as I am looking for a node that often is only .5 to max 1.0 wide and this gives me a easier way to determine it.

1. Shoot ONLY in early morning or evening in no wind conditions.

2. minimum of 300 yards prefer 400. I have found that seems to be the ideal distance for enough vertical dispersion as the bullets walk up and close enough to see each separate bullet impact with good spotting scope on white target. Shorter makes it to difficult to determine impacts and longer makes it too difficult again to see any impacts.

3. 35P chrono is used.

4. Minature paper target at bench to plot each round and another sheet to write down each MV for each round. That way I do not lose track of any bullet shot as each is numbered on plot sheet and anytime I go down range to verify impact. I also mark each shot on the 35 P paper as it is shot.

5. Minimum of 1 minute between shots from starting dirty bore, I usually zero at that distance on another target at the side to confirm accurate zero for bottom of ladder target which is normally large plain white cardboard with 1" aiming dot near bottom. I use .3 grain for large cases and .2 for smaller cases as increments.

6. If I am not 100% sure of bullet location, I either walk down or I often use use colored magic markers(4-5 colors) alternating on bullet tips which show up on target. No they will not vary impact points on target. That is used all the time at 1K BR to identify any crossfires on your target.

7. MV as you go up will be linear (ie roughly same FPS each bullet) until you hit a node and then it tends to decrease dramatically for that 2-4 shots and then jump linear again. You will see 3-4 rds with small MV variances normally in the node and then jump dramatically again. You can see on a magnum a jump of 20 FPS and then 3 bullets around 6-8 fps along then it will jump again back to around 20. This is only an example, not always.

Combination of bullet AND MV grouping confirms node and is usually easy to see when you compare the two!! You will have multiple bullets with similar vertical impacts and very low dispersion on MV.

8. I pick a middle node, shoot groups to confirm basic accuracy and ES, SD nodes. I normally find 2 mabye three nodes, and one will be in the MV range I am looking for. Many times the top one is at the starting of high pressure point, so often do not use that one. Middle of the node gives me enough variance on temps and other factors that I am not out of the node on any given day. I do not focus on the lowest ES/SD. Once I find a node then it is an "acceptable ES/SD and tight grouping that is confirmed. I normally shoot for single digit ideally but low teens is acceptable with the grouping.

I determine pressure by case head expansion measured with a blade mic, primers (but not always accurate as some are softer than others) etc. It is a combination of everything that leads me to determine I am at high pressure. I take it until is see firm signs of pressure and then stop even if I have not shot all the shots IF I am at an acceptable MV and see good nodes.

9. I then try groups at various seating depths at my best grouping and see what depth it likes. For a single shot gun start, .010 in the lands and come out. Magazine gun, start at max magazine COAL and in from there. I start .010 in, come out at .030, .050, .080 and .120 IF a single shot gun. One will be much tighter and then work in between to find the place normally down to .010.

10. If the gun will not shoot 1 MOA, that makes shooting a ladder a little difficult as you do not know what is the real vertical or 3-4MOA grouping "inability", so IMO it is not for every gun.

11. If a gun will not shoot with all this, then another ladder with another powder or bullet combo.

I have proven this is repeatable and capable of taking a new rifle to winning in competition is under 50 rds fired.