working up a load for .223, charge increments?

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Seeker2

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Hi,

I've never loaded a smaller cartridge before now. I was about to start loading at .5 gr increments, but wondered if a smaller increment is the norm for smaller cases. I was thinking about .3gr? Looking for insights.
 
The smaller the cartridge case and its case capacity the more sensitive the case is to the amount of powder charge.

The .223/5.56 cases can vary approximately from 28.0 grains of H2O to 30.6 grains of H2O and this can cause a variation of 5,000 psi. Most American brands of .223/5.56 cases are closer to somewhere in the 30.0 to 30.6 range.

Bottom line with smaller capacity cases like the .223/5.56 0.2 is what I use and what I see recommended at many websites.

NOTE, my Savage .223 with a 1 in 9 twist has a longer throat than my AR15 rifles, (.0566 vs .0500) and 1 in 12 and 1 in 14 twist rifles have a shorter throat. (.0250)
Meaning I can load my Savage .223 "warmer" than loads for shorter throats listed in reloading manuals. I have a MagnetoSpeed Chronograph and was surprised at my lower velocities developed for a 20 inch A2 HBAR AR15 fired in my Savage.
 
Seeker2 said:
Hi,

I've never loaded a smaller cartridge before now. I was about to start loading at .5 gr increments, but wondered if a smaller increment is the norm for smaller cases. I was thinking about .3gr? Looking for insights.
Click to expand...

The increments are somewhat arbitrary. I think the critical part if you plan to do a ladder test is to do it at 200-300 yards if possible, and measure the velocity of every shot and identify the position of every single shot. When you are done, ignore the horizontal position, but plot the vertical elevation of every single shot vs the velocity of every single shot. In Excel it is called a Scatter Graph. It will tell you where the velocity sweet spot is.
 
To my way of thinking you waste more bullets and powder going in .2 or .3 increments. Big Ed bullets and powder are much more expensive in canada.
If I am doing 223 and the max book load is 26gr lets say. I'll load , 3 at 24, 3 at 25 and 3 at 26. most loads in most calibers are most accurate at the top end of the scale. Or beyond. FS
 
Fassteel said:
To my way of thinking you waste more bullets and powder going in .2 or .3 increments. Big Ed bullets and powder are much more expensive in canada.
If I am doing 223 and the max book load is 26gr lets say. I'll load , 3 at 24, 3 at 25 and 3 at 26. most loads in most calibers are most accurate at the top end of the scale. Or beyond. FS
Click to expand...

The Sierra link I posted is a ladder test and only one round is fired for each load. Meaning it uses less bullets and powder than the OCW test with three or more shots per target.

With the ladder test you look for when several bullets hit at the same horizontal level and that is the node to work on for more development.

Below the single fired rounds numbers 4, 5, and 6 are on the same horizontal elevation and the node to develop further. And only 9 rounds fired instead of 27 or more rounds fired with 3 shot groups. After the single round test you then play with seating depth for the final tuning with three or more rounds fired per group.


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The only downside to this test method is it should be shot a 200 or more yards, and the OCW test is done at 100 yards but uses three shot groups minimum.
 
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Ed he has still fired 27 rounds to determine his information, but I do like the theory providing that the original powder he has chosen works well with his selected bullet.
 
Fassteel said:
Ed he has still fired 27 rounds to determine his information, but I do like the theory providing that the original powder he has chosen works well with his selected bullet.
Click to expand...

And you will fire over twice that many rounds with the OCW test method. We lost our 200 and 300 yard ranges at my range due urban encroachment and they are now high dirt banks to lower the noise.

Meaning I have to do it the old fashioned way and fire more rounds at 100 yards. But nothing beats a good day at the range and workup loads.
 
0.2 for me, when I seem to find one that it likes, I do a few more at + and - 0.1 to see if it likes these any more. After that I'll play with seating depth.
 
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