Satterlee ladder test question

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mungojeerie

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I have a question about the Satterlee ladder test while working up a load.
The method described by him states that he starts 1.5gr below his max load then works his way up at .2gr intervals.
Everything I've always read and have been told is to ALWAYS start at the minimum charge.
Some of my cartridges have a diff between min and max of like less than 3gr so no big deal to do a ladder test for the whole spread at .2gr and you still only have 11 rounds, other cartridges would take over 40 rounds to test the whole spread at .2gr intervals.
Is it safe to start at the half way mark and work up, inspecting each case for signs of pressure and noting velocity of course?
 
For "standard" size cartridges, .308, .30'06, etc, I go up in half-grain increments. 0.2 gr would be appropriate for .223 or pistol size cases.

Where to start depends on what cartridge you're dealing with. Normally I start 2 grs below max. The .30'06, for instance, has a lower max pressure rating than the .270 Win, in spite of having the same basic case and being chambered in the same rifles, so I feel more comfortable starting closer to the max listed for that one. The 7x57 is another example, where load data is typically watered down.

For lever action cartridges, I don't exceed book max, because by the time you see traditional pressure signs you've exceeded the design limit of the action by a considerable margin.
 
You can start lower than 1.5 if you wish. I usually start 2.5 grains lower and go up 0.2 or 0.3 depending on the cartridge. If over 50 grains, I do increments of 0.3, if less than 50 I do 0.2. I exceed book max by one increment only. You want to catch the velocity node wherever it is. Sometimes you might have 2 velocity nodes. This method really works, it is fast and quite often gives sub moa at middle of velocity node, more than enough for hunting. Target shooters play a bit more on COL to fine tune their loads.
 
Im not sure what the concern here is with loading below minimum.

If your intent is to find accuracy node as close to max as possible, normally that will require you to drop about 5% below max and work back up.

Going lower will not reveal any benefit, but will consumer more materials and a marginal amount of barrel life. Similarly, working .1, .2, or .5 increments has a trade off of more materials, but you will get a better data set. To each their own.

Its this idea of NEVER go below that I dont understand. What do people think is going to happen below minimum?

In laboratory testing I routinely go well below minimum, sometimes as low as 50% or 30% of max. Like 18 gr of varget in a .308. Done this hundreds of times. Seen it done thousands of times. Never seen an issue.
 
9.3mauser said:
For "standard" size cartridges, .308, .30'06, etc, I go up in half-grain increments. 0.2 gr would be appropriate for .223 or pistol size cases.

Where to start depends on what cartridge you're dealing with. Normally I start 2 grs below max. The .30'06, for instance, has a lower max pressure rating than the .270 Win, in spite of having the same basic case and being chambered in the same rifles, so I feel more comfortable starting closer to the max listed for that one. The 7x57 is another example, where load data is typically watered down.

For lever action cartridges, I don't exceed book max, because by the time you see traditional pressure signs you've exceeded the design limit of the action by a considerable margin.
Click to expand...

I would be loading for .22-50, .270wsm, 6.5cm, 7mm RemMag & .338 RemMag. The load that Im using for the 6.5cm is the one that only has 11 cartridges at .2gr intervals so thats an easy one, but the .270wsm is another story spread between min and max of 7.4gr.
 
mimile said:
You can start lower than 1.5 if you wish. I usually start 2.5 grains lower and go up 0.2 or 0.3 depending on the cartridge. If over 50 grains, I do increments of 0.3, if less than 50 I do 0.2. I exceed book max by one increment only. You want to catch the velocity node wherever it is. Sometimes you might have 2 velocity nodes. This method really works, it is fast and quite often gives sub moa at middle of velocity node, more than enough for hunting. Target shooters play a bit more on COL to fine tune their loads.
Click to expand...

Thank you, I appreciate the comments. starting 2.5gr below sounds good. most of my cartridges are over 50gr so maybe I will try .3 increments as suggested.
 
Cameron SS said:
Im not sure what the concern here is with loading below minimum.

If your intent is to find accuracy node as close to max as possible, normally that will require you to drop about 5% below max and work back up.

Going lower will not reveal any benefit, but will consumer more materials and a marginal amount of barrel life. Similarly, working .1, .2, or .5 increments has a trade off of more materials, but you will get a better data set. To each their own.

Its this idea of NEVER go below that I dont understand. What do people think is going to happen below minimum?

In laboratory testing I routinely go well below minimum, sometimes as low as 50% or 30% of max. Like 18 gr of varget in a .308. Done this hundreds of times. Seen it done thousands of times. Never seen an issue.
Click to expand...

My questions was with starting a load above the minimum as opposed to at the minimum, wasn't concerned about below minimum.
 
Cameron SS said:
Fair enough. I misread. Apologies.

If the min/max is more than 2 grain apart I dont think ive ever started at the book minimum.
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No worries. So if the book min/max is 51.1gr/58.5gr where would you start? does 56gr sound reasonable to start at with .3gr increments which would give me 9-10 data points (if your curious .270wsm, IMR-4831, I know H1000 and some others seem to be a preferred powder, but I have a lot of IMR4831 so would like to see how it does)
 
Well - The point to starting at minimum load is to see if your rifle and/or load combination is "hot". If you've shot the rifle before, and it behaved civilly, then you can take liberties with future loads. With a known rifle, I will start load development a grain or so below mid-point (308 cal, etc). I dont do ladder tests, as they can be inconclusive for hunting-grade rifles. I do trials of 3 shot groups, with powder increments of half to a full grain. Rarely, is the sweet spot near max - I dont like running max loads in the first place... In some cases I will try to fine tune between the first trials, with some additional increments. Works OK for me.
What I do find is that a good load, particularly a specific bullet weight and configuration, will show promise right out of the gate. Other bullet weights, a fella could go blue in the face trying to get them to shoot.
 
OP, when you're working up loads for a rifle that is new to you, then it's prudent to start off with minimum loads. Not a bunch of them but one or two so that you can see what's happening in that chamber with the components you've assembled.

If you know the rifle and are just changing components to find an accuracy node you're comfortable with and depending on the case capacity, then you can start somewhere in the middle of the suggested loading table.

Smaller cases have a much tighter range than larger cases.

Most smaller cases will show the best accuracy node right around the middle. Sometimes a bit less or a bit lower depending on the individual rifle and components.

Most, not all larger mid range cases and magnum cases perform best very close to maximum charges. Not always, that's why you start with a lower charge.

The other thing is, today cannister grade powders are way more consistent than they were ten years ago and especially twenty plus years ago.

Back in the day, if you didn't purchase large quantities of any lot of powder/components, you almost had to start all over again with every different lot of powder or component change. Sometimes, the powder lot could be radically different, especially in small capacity cases.

If your previously worked out load was close to maximum, the new lot of powder, primers, bullets, cases could make that load over maximum pressure very quickly.

You likely wouldn't suffer from a catastrophic failure but some damage could be done to bolt faces from primer blow outs or case separations.

There is another thread here concerning D8208xbr Dominion powder as sold by Canada Ammo for a very decent price when other powders were unobtainable at any price.

It came in two different lots and they were much different from each other and one wasn't even close to its contemporary IMR type that the suggested loads were taken from by many experienced handloaders that are used to cannister grade standard deviations in burn rate from lot to lot.

Many experienced excessive pressure issues because of this.

Rule of thumb, with loads in cases like the 22 Hornet to 223rem .1-.2 grain increments when working up a load. 22-250 -308 .2-.5 grains unless the increments are showing excessive powder fouling on the neck/shoulder/case walls then go to half grain incremets until you're close to maximum, which is easily discernible when you no longer see propellant fouling below the case neck. The propellant fouling below the case neck is an indication of low pressures, not allowing the case to expand enough to block the gasses from coming back. You may even see backed out primers or excessively flattened primers.

If you have excessively flattened primers and your case shoulders/necks are shiny, it's often an indication your pressures are extreme.

With magnum cases I will shoot a few with minimum charges just to be comfortable and work up the next half dozen loads one full grain each until primers start to flatten and propellant fouling becomes minimal. Happily, this is also usally very close to the accuracy node I'm looking for.

Once you start loading cartridges such as the 30-06, one tenth grain either way will not usually be noticeable, unless you're very close to maximum or below what would be a minimum load for your particular rifle.

This is a good place to start, then build up on from your own experience.

Each rifle is an entity unto itself, only on very rare occaisions are two rifles equal in performance, no matter how close they measure out or even if you're using identical components.

Some come very close though and with todays CNC manufacturing most are close enough that nothing gets critical without something negative to performance being done.
 
mungojeerie said:
No worries. So if the book min/max is 51.1gr/58.5gr where would you start? does 56gr sound reasonable to start at with .3gr increments which would give me 9-10 data points (if your curious .270wsm, IMR-4831, I know H1000 and some others seem to be a preferred powder, but I have a lot of IMR4831 so would like to see how it does)
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Yeah that sounds about. But one other point. If is this a new rifle or with a new powder Id add an extra margin of safety. If ive already done a bunch of loads and I know with my chamber brass etc and my gun tends to end up in a consistent range of min maxs than Id be more comfortable not starting at rated min.

Keep in mind you are your own QA and Safety Supervisor.
 
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mungojeerie said:
No worries. So if the book min/max is 51.1gr/58.5gr where would you start? does 56gr sound reasonable to start at with .3gr increments which would give me 9-10 data points (if your curious .270wsm, IMR-4831, I know H1000 and some others seem to be a preferred powder, but I have a lot of IMR4831 so would like to see how it does)
Click to expand...

No experience with 270 wsm but your method would be good. 56 grains, which is 2.5 gr below max is good. Go one increment above max just in case you have a node around max dose.
 
I think you would be better off increasing the range of your test. Bump up your increments to 0.5 grains. Why do you think the optimum load is near book max?
 
This is a Satterlee ladder test. if you go up by big increments you might miss the node for velocity. 0.2 to 0.3 increments are great.
 
If everything is new to you, definitely start at min printed loads. I have locked up rifles with 'known' loads due to variations in powder, and bullets from brand to brand/lot to lot. so, I now ALWAYS verify what I am playing with before I get into load tuning.

I call it finding your goal posts..... why not take ONE rd at each full grain step and see how it reacts in your rifle. 8 rds will cover the load data and you will know real quick the good, bad and ugly. I assume you are a novice loader and this will confirm your rifle and ingredients. If you use a chronie, it will tell you the speed range as well.

So if you are mid charge and your velocities are already at the hot end, you now know your rifle is 'fast'... and don't need to add all the powder.

conversely, you approach max loads, there is zero pressure signs AND the velocity is way slower then expected, it gives you the option to go over max as your set up is running 'slower' then expected.

Factory rifle barrels can vary a bunch in bore/groove dimensions. Why you will get variations in what shooters report for the same load set up.

Know that the same brand/type of powder can vary from batch to batch. The load data was generated with one lot and the formulation you have might just be different. quite common with the Hodgdon powders I have used. FYI, Varget has 3 options that might be sent over to NA (fun chatting with Aussie shooters in the industry)... some Alliant powders have been more consistent for me... assume nothing, test everything.

Hope this helps.

Jerry

FYI, i will work up my load tune in 0.2 or 0.3grs BUT I will shoot 2 rds per step at paper 200 to 300yds out. You are going to save alot of time chasing load tunes this way as the 2nd shot gives you a ton of info on how the barrel is reacting. Good shooting loads will typically have smaller ES/SD... small ES/SD does not mean the load will shoot well... and often, really small ES/SD can lead to not so good shooting far out.
 
Thank you Bearhunter, Cameron SS, mimile and Mystic Precision.
One of the most frustrating things with this is that I have limited opportunities to get to the range, between my schedule, the range's schedule and the constraints of daylight. I did do two ladder tests yesterday, one with the 6.5 creedmoor and one with the .338 win mag. the .338 was less promising with my load for detecting a node, the 6.5 had some strange anomalies but it still gave a nice looking sine wave and I did pick a node to try some rounds at. we will see what happens from there. I have some serious confusion with powders for the .338 and their min/max loads. I will post about that in another thread.

Another puzzling issue is that all of my rounds have MV signifigantly slower that what book data suggests I should expect, even at the max load. thoughts?
For instance the 6.5cm shooting 140gr with RL19 I expected a MV of 2743fps at a max charge of 43.7gr, I shot 12 shots at .02gr increments starting 2gr below max and working my way up to max. I experienced MV starting at 2298fps and maxing out at 2458fps, the max mv was below the expected mv for the min charge which was 2605fps at 41.5gr.

And the .338 win mag shooting 225gr with IMR 3031 I had expected to reach a max mv of 2667fps at a max load of 54.8gr, but I only achieved a max mv of 2516fps.
 
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Mungojeerie,
What is the source for your RL19 and 6.5 CM loading data? I looked at Alliant website, they do not have that combo.
 
I don't know how reliable xxl-reloading.com is. I do not reload for 6.5 CM but from what I read over the years, most people would rely on H4350 at around 40-41.5 grains with 140 grains for 2600-2700 fps.
 
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