Load ladder building

[conan32120]

When I'm looking for a powder/ bullet combo that my rifle likes I have to figure out how to build my ladder. Generally I keep my ladder in an MTM sliptop 20 round box. Now to have a viable ladder I load 5 'rungs' of 3 rounds each. I also figure that .5 grain increments will give me a rough idea where to focus my attention. Problem is where to start some ladders as load data can show a broad range of powder weights for a given bullet. I usually start somewhere in the middle. Lack of range time and high Temps most definitely restrict my search. Barrel heating and round count through said barrel also affect my choices. How do you all hunt for that perfect load?:

 

[rfwobbly]

Pretty much the same, except I allow the Load Range to pick my increment. With a dense pistol powder a fixed increment of 0.5gr could be to much, and with a rifle powder a fixed increment of 0.5gr could waste a lot of my time loading and testing rounds where the difference can't be detected.

• If the book's Load Range is from (say for instance) 3.2 to 3.7gr, then an incremental step of 0.5gr is out of the question. I divide the Load Range of 0.5gr (3.7 minus 3.2) by 5 and get an increment of 0.1gr. Thus my loads are... 3.2, 3.3, 3.4gr etc.

• Similarly, if the Load Range is 26.3 to 35.4gr (a span of 9.1gr), then my increment becomes 9.1 divided by 5, or 1.8gr. Thus my loads are 26.3, 28.1, 29.9gr etc.

If the biggest difference occurs between Load #3 and Load #4, then I can always go back and subdivide that specific range.
.

 

[conan32120]

I always thought if I used increments that large I could completely miss the sweet spot

 

[AK Hunter]

I subtract the Min from the Max load gr weight, then divide by 5 & load 3 rounds ea. to the closest gr weight for starters. Then when I find the area that the gun likes I go back to load .1gr increments for testing.

 

[film495]

I subtract the Min from the Max load gr weight, then divide by 5 & load 3 rounds ea. to the closest gr weight for starters. Then when I find the area that the gun likes I go back to load .1gr increments for testing.

can you give an example of this? I think I get what you mean, but not sure. does this end up 5 steps in the ladder from low to high as a start?

 

[AK Hunter]

can you give an example of this? I think I get what you mean, but not sure. does this end up 5 steps in the ladder from low to high as a start?

If you want it to come out to only 5 increments you just divide by 4.
If I was to do a ladder for say 308 Winchester 150gr using Varget the book calls for it to be a Min of 44.0gr & a Max of 47.0C (don't worry about compressed loads if the book says it ok). Subtracting the min from the max gives us 3 divided by 4 gives us .75 rounded to .8gr. That would give us a ladder of 44.0gr, 44.8gr, 45.6gr, 46.4gr, 47gr. (remember to not go over the Max) After shooting these if I find that the load 45.6gr & the 46.4 is the most accurate for my gun, I would load .1gr each between 45.6gr & the 46.4gr to fine tune the best accuracy.

 

[Varminterror]

I’m not a fan of 1/2 grain increments unless the case is absolutely massive. Most reloading equipment can’t actually produce a proper 0.2grn increment, but if a loader does have the capability, 0.2grn steps are great, 0.3grn steps with conventional reloading gear. There’s just no way to position a node which is 3-4 tenths wide in a 1/2grn ladder and have any hope of finding it.

 

[JFrank]

When I'm looking for a powder/ bullet combo that my rifle likes I have to figure out how to build my ladder. Generally I keep my ladder in an MTM sliptop 20 round box. Now to have a viable ladder I load 5 'rungs' of 3 rounds each. I also figure that .5 grain increments will give me a rough idea where to focus my attention. Problem is where to start some ladders as load data can show a broad range of powder weights for a given bullet. I usually start somewhere in the middle. Lack of range time and high Temps most definitely restrict my search. Barrel heating and round count through said barrel also affect my choices. How do you all hunt for that perfect load?:

Use two shots of each appropriate to your cartridge increment extended to signs of pressure and don’t overlook the low node ( they travel well) ..
Stay tuned
J

 

[kmw1954]

Use two shots of each appropriate to your cartridge increment extended to signs of pressure and don’t overlook the low node ( they travel well) ..
Stay tuned
J

When I shoot ladders I am looking for accuracy nodes, could careless about bullet speed until after I have found a workable node. I load and shoot round robin fashion 3 rounds. All loaded at .3gr increments. Once I find one that looks good I load again those 2 rounds and the in-between and .1gr above and below. Many times I find the node to be .4gr wide or close enough it could be.5gr with the same point of impact and same general group size.

A number of tests with different bullets and powders I found the lower node to be much more accurate, consistent and repeatable than the upper node. But then again with other combinations it went the other way too.

 

[AJC1]

I live and die by 1% or .1 grains in pistol or rifle. List what your actually loading for more specific advice

 

[conan32120]

In answer to your question, rifle is a .308 savage axis, bullet is 150gr hornady fmj, powder is CFE223. Hornady manual says range is 42.4 to 49.6. I would believe that somewhere in that 7.2gr spread is a load that my rifle might like. The temp here is a wonderful 95 with a heat index of 105, so barrel heating will occur quite rapidly and I can't dedicate a full day to shooting. My query is to inquire how others would deal with such an issue

 

[Howa 9700]

I live and die by 1% or .1 grains in pistol or rifle. List what your actually loading for more specific advice

I went thru the same process as OP in past year or two, and what finally made sense to me was to use 1% of published MAX load as my increment, then do 10 of those increments starting at MAX and backing down. You can round up or down, but I tend to round down. 1% works as a reasonable increment if total load is 58 grains or 28 grains.

For example........MAX load is 47 grains. Increments would be 47 x .01 = .47 rounded down to .4. So load ladder increments are then then MAX of 47.0, then 46.6, 46.2, 45.8, etc. This gives you roughly a 10% range, which is where most start loads start.

I always include increments to max published load data as those often reveal an accurate load at near factory level velocity, using a full case of powder whenever possible. Seems there is often a correlation between full case of powder.....bordering on compressed.......and best accuracy.

But backing down and working up also important. Have found at least one powder that ran into excessive pressure several full grains below published max. Scary to think about what might have happened by starting at max with powder.

PS: Forgot to mention.......I load 3 each of those increments, fired over a chrony. Tested at 100 yards. Best group at close to max charge and desired velocity wins.

 

[Laphroaig]

I'd get a chronograph, load 24 rounds in .3 increments, and shoot a ladder low to high in the Saterlee fashion. The velocity node(s) would be my starting points if I wanted to compare loads. FMJ's and only one choice of powder doesn't warrant multiple range trips and pinpoint refinement IMO.

 

[JFrank]

Here’s a couple ladders from yesterday, looking at neck tension as well as basic charge rate.

Bottom line is to find the stable overlapping charge rate. In my case ( 30.7) but be sure to look at that low node as well.

 

[kmw1954]

After reading all this again I'm guessing it comes down to what your expectations and required results are.

If just looking for Minute of paper plate at 300 yards it would be different than when looking at 1" targets for score at 300 yards. I am shooting for the later.

 

[conan32120]

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