Procedure for working up a load

[Ooglar]

I just started reloading and was wondering what procedures to go through to make accurate ammo tailored to a gun. So far I've rolled about 500 rounds of 9mm without incident (they all went boom and hit what I was aiming at, which is all I ask from a handgun) and just tested my first batch of 223. The 223 grouped around 3-4moa. What variable do I change first, powder charge? Bullet type ( I am using cheap winchester powerpoints)?

Also, in terms of reloading what is the functional difference between 556 and 223. My above load was 223 data loaded into lake city brass.

Thanks

[frankski]

A short answer is read this article from Accurate Shooter about loading .223. http://www.accurateshooter.com/cartridge-guides/223rem/

Also read this: http://optimalchargeweight.embarqspace.com/#

The longer response is.. a lot of questions. Like, in what rifle are you shooting these .223 reloads? AR or bolt? Have you checked the usual problems like loose scope or action screws (bolt action). What is baseline accuracy - how accurate is it with factory match ammo? You also have to eliminate your own shooting skills from the equation - How well do you shoot consistently (that is, are you sure the load is the issue)?

Edited to add: Barrel twist rate vs. bullet weight could be a big factor - see the Acc. Sh. article.

[M&P Chris]

Going off what frankski said: what twist is your barrel? What grain bullets are you using?

What is your OAL overall length and what powder?

[PAwhitetailbowhunter]

Barrel Twist to bullet weight would be my first consideration. Then rifle type, AR or Bolt to consider seating depth. I have had great luck with Varget and H335 powders with 69-77 grain bullets out of a 1-7 twist 20" AR. Keep asking questions and read everything you can get your hands on. Good luck be safe and enjoy reloading.

[Hawk]

What rifle?
What's the twist rate of the rifling?
What scope?
How are you steadying the rifle?
What are the specs of your first test load? (powder, powder weight, bullet weight)
What distance are you getting 3-4 MOA? (how many rounds make up that group?)

[daschnoz]

223 data in a 556 chamber - you're good. 556 runs at higher pressures AND has more free bore. You're running LC brass (mil spec). Mil brass tends to have thicker wall = less internal volume = higher pressure for the same powder charge vs commercial brass. If you're not pushing max 223 charges, you should be ok. I generally load blasting ammo in 556, so I load at 75% * and call it a day.

* 75% of the span between min and max:
for example, 308WIN ,150gr pill, W748
min = 40
max = 50
difference = 10
fraction = 10 * 0.75 = 7.5
load = min + fraction = 47.5



More good info on the difference:
http://www.luckygunner.com/labs/5-56-vs-223/



What is the load you tested? Bench rest or off hand?




As for working up a load.
Pick a bullet and a powder. Determine what you want the OAL of the rounds to be. When working up a load like this, you only want to change 1 parameter at a time. Using this method, ONLY CHANGE THE POWDER CHARGE.


Load rounds starting at the minimum charge, work up to the max charge in increments. (I use 0.2gr for faster shotgun/pistol powders, 0.5gr for slower burning rifle powders.) Load up in groups of 5-10 rounds. Put each group in a zip-lock bag and mark the powder charge.

From a bench rest, shoot the rounds from each bag on a target; a new target for each bag. Make sure you mark the powder charge on the target. You're not concerned about POA vs POI. What you're looking for is group size, so it doesn't matter if your POI is 2" low.

Now, at the end of the day, line up the targets, low charge to high charge. You should see a trend towards the accurate load range. If the group tightens up going toward either extreme, you know that is where you want to be - either at the extreme low end or the extreme high end. If the group tightens then spreads back out, you know that the ideal powder charge is somewhere between the charge on the 2 targets. Repeat the same procedure as above, but use 0.1gr increments.

So, for example:
Your 2 best groups are 21.0gr and 21.5g. I would start at 20.9g and go to 21.6g in 0.1gr increments. You may find that all of the groups are the same size (or too similar to measure the difference without spending a fortune on computer measuring equipment). You may find that anything between 21.1 and 21.3gr gives you the best group. Most scales have a tolerance of +/-0.1gr, so you're hitting those limitations. You're really 21.2gr +/- 0.1gr, so call it 21.2gr.

You may need to go through a few powders of differing burn rates (IMR3031, either of the 4895s, H335, IMR4064) before you get to the level of accuracy that you want. If you're still not getting the results you want, change the bullet and re-do.


Another thing that is annoying is that guns tend to be like women - what works for one may produce the totally opposite result from another. You may find that gun #1 shoots its best group with IMR3031. Gun #2 my group like a shotgun blast with 3031, but REALLY likes 4064. BOTH may be not great, but may be acceptable with 4895. The nice thing is that whatever powders you decide aren't "perfect" can be used to make Sunday afternoon blasting ammo - so it's not a total loss.



Either way, trigger time is never a bad thing.

[jw34]

Really ? No ones going to post a reply based only on the title of the thread ?

I usually like to start by dimming the lights and putting some Barry White on the stereo.



Apologies for the crass interruption. You may now resume technical talk.

[daschnoz]

Really ? No ones going to post a reply based only on the title of the thread ?

I usually like to start by dimming the lights and putting some Barry White on the stereo.



Apologies for the crass interruption. You may now resume technical talk.

[God's Country]

Really ? No ones going to post a reply based only on the title of the thread ?

I usually like to start by dimming the lights and putting some Barry White on the stereo.



Apologies for the crass interruption. You may now resume technical talk.

I was considering it, but let it go.

[Remington788]