Let me make sure I've got my head wrapped around this load development process

G

Great Crouton

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I've been reloading for a while now but basically just .40 for my pistol. I've whipped up a handful of .30-30 simply because I wanted to try out rifle reloading by I've never really developed a load of my own for any of my rifles.

Now that I have an AR that's shooting factory cartridges beautifully I wan't to develop a load for it. Got everything I need, recieved my shipment of 1000 1x fired .223 cases. I have 2 pounds of both IMR 4064 as well as IMR 3031.

I've settled on trying out the IMR 3031 with 55gr SPT bullets, CCI primers and Remington cases of which I've prepped 100 of.

My Lyman manual shows a min of 22gr and a max of 24.5.

So my thought process was, load up 10 rnds in .5 gr increments spread between 22 to 24 grains for a total of 70 cartridges. (10 at 22gr, 10 at 22.5, 10 at 23 etc...)

I'll take these to the range and see what load seems to do the best and then further refine? Assuming for example the 23.5gr batch does best, I can then load up a similar batch but this time going up in .1gr increments from 23gr to 24 gr until I find the magic number.

Is that the right idea?
 
5rnd groups at 0.5gr increments off a rest. Check for high pressure signs closer to your max powder charge. If you develop a load you really like, you can chrono it and you can use that to calculate bullet drop for longer ranges. Or if you don't own a chrongraph, shoot 100yrds then 200yrds and note how much bullet drop you got. You should be able to calculate your bullet speed by that.

Personally I like to use the chronograph. :p
 
Trinimon said:
Personally I like to use the chronograph. :p
Click to expand...

I would like too as well. Add that to the loooong list of toys I'd like to buy. That will be later on though. Right now, I need to pick up a powered case prep tool of sorts. Prepping 1000+ cases by hand is tiresome. Love reloading and all aspects of it, just need to speed it up a tad.
 
Great Crouton

Go back and look at your Lyman manual, it gives SAAMI loads for .223 and the AR15 rifle. "BUT" the 55 grain loading data you are looking at is for a short throated commercial SAAMI chamber. All the loads with an asterisk before the bullet weight are AR15 loads and they start at 69 grains. When you use this type data in a AR15 rifle the chamber pressures will be approximately 8,000 psi "LOWER" when shot from the AR15 rifle with its longer throat.

223_zps6248614d.jpg


barnes-pressure_zps9347fe41.jpg


Now to your workup loads, and your just starting to get your feet wet reloading rifle ammunition so just play it safe to stat off.. Start at the suggested starting load and work up in half grain increments, then as you get near maximum start using .2 grain increments.

After you fire each three to five shot group and powder charge examine the primers, the base of the case and neck, and get familiar with the pressure signs from low to high. Learn to "read" the primers, at first you will see the primers are protruding from the bottom of the case and as the pressure increases the primers will become flush with the base. Then as the pressure increases the primers will become flattened, to be safe use factory loaded ammunition as your primer baselines, meaning how flat the primer get.

Nothing is written in stone in the reloading manuals as each firearm tested will be slightly different so pressures can and will vary.

I have two AR15 rifles and a bolt action Savage .223, the Savage throat is "LONGER" than my AR15 rifles and this factory Savage does "NOT" have a SAAMI throat. Meaning I can load the AR15s and bolt action "HOTTER" than manual data.

Below are two links from the Sierra manual for the .223/5.56 and their separate loading data.

Bolt action .223 rifle load data.
http://accurateshooter.net/Downloads/sierra223rembolt.pdf

AR15 load data.
http://accurateshooter.net/Downloads/sierra223ar.pdf

Now look at your 30-30 fired primers, they will be protruding from the base of the case because the chamber pressure was only 38,000 cup or 42,000 psi. Your start loads for the .223/5.56 will be the same approximate pressure as your 30-30 but as you increase they will go to approximately 52,000 cup or 55,000 psi. At these higher pressures your primers will be flush with the bottom of the case and flatter at the edges of the primer as the pressure increases.

Now remember this, the pressures listed below are all the exact same pressure and are just measured differently. Meaning the .223 and 5.56 NATO are both loaded to the same rated maximum chamber pressures, with the throats of these rifle taken into consideration. (see chart above)

52,000 cup SAAMI copper crusher method
55,000 psi SAAMI transducer method
62,000 psi European CIP and NATO transducer method with the pressure measured at the case mouth.
 
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Your ideas are ok, except that unless it a special heavy barrel custom rifle, I would skip the 0.1 fine tuning.

With an Ar you want to find the lower limit of what cycles the action, and work up to find what is 100% reliable and groups well.

I shoot CQB (35 yards) so power is not a requirement. I load near the low end of the curve, to reduce recoil. This aids shooting fast.
 
Thank for that info, bigedp51,that's awesome! And coud certainly shed some light on some things I noticed.

That link you provided for the AR15 load data shows a starting point of 23.1 where Lyman suggests 21. I stated off at 21 grains and increased in .5 increments until I got to 24 grains. Always went "bang" but had cycling issues. It ejected just fine but would not pickup a another cartridge from the magazine. It wasn't until I got to the 23.5 load that it started to cycle properly again.
 
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