Using my .223 load in 5.56 brass

[Rtheurer]

Doc and Necchi

I can say I have never tested brass older than late ninties in my search for the truth, so that may very well be the case ( pun intended) with the 70's brass. True the advice above about taking a couple quick and simple H2O measurements would solve any guessing game for sure. Now Im going to have to find some brass from the 80s and 70's just quench my currosity.

Doc, I now have a cup of coffee in me and my blood pressure is normal. I do get my panites in a knot about this very topic and have researched and tested it to death to find out the truth. After a fella goes thru all that time and energy i guess i feel I am qualified to comment on this topic. Internet is one thing... But printing it on paper by X number of gun writers really gets me going Ha!
I didnt intend to discredit you so if you felt that way im sorry. Learn new stuff here almost everyday with a great knowledge base that are members here. I believe a guy could learn more in one week than 10ys blundering through life without this site.

Hope all is well.
RussT

 

[bigedp51]

How many times in this forum has it been stated that there is no relation between case weight and internal capacity. Below is from 223 Rem + 223 AI Cartridge Guide from this website.

"From a reloading standpoint, the important thing to note is the rather substantial variance in case capacity from one brand of brass to another–as much as 2.6 grains! So, you cannot assume that a particular “pet load” will work if you change brass brands–you’ll have to do new testing. Whenever you get a new batch of brass, you should measure at least a half-dozen to get the average actual H20 capacity. Compare this with your other cases. You may need to add or subtract powder to maintain a given velocity. Or, if you are already at max pressure levels, you will have to reduce the load if your new batch of brass has less capacity."

From the 1978 Handloader's Digest
Case Capacitiy Tables
By Ken Waters
Tables revised in 1974

.223 Remington case weight 95.1 grains, internal capacity 28.5 grains of water
5.56 NATO case weight 97.8 grains, internal capacity 28.3 grains of water

 

[necchi]

How many times in this forum has it been stated that there is no relation between case weight and internal capacity.

See this jack can post pictures and add funny little quips (in his world) and belittle others but fails to be able to properly interpret the very data he links, there is obvious correlation.
Heavier brass has less capacity,,
Oh, But Wait,,
See the one sample highlighted in bold? That one bit of info must indeed invalidate the entire chart!

Another thing one must consider while weighing cases is the brass alloy.
That's right "brass" is really a mixture of several different metals
Nobody really knows where or how PMP in South Africa makes or obtains this alloy, maybe they got a good buy from Somalia that year?
Must be the wife likes him a bit drinky every day, he's happier that way, things aren't so confusing.

 

[bigedp51]

A little reading and less sewing and the light bulb might come on necchi, and you even talked about brass alloy weight.

On top of this the OP has mixed range pickup brass that's not from the same lot.

Chamber volume affects peak pressure a great deal.
But chamber dimensions don't represent a variance.
I'm talking about the affects of containment variance as an early contributor in peak pressure, which ultimately affects barrel time of bullet travel.

Try this; Weigh some new/prepped brass to match and fire across a good chrono.
Now neck size it, reload and fire again over a chrono. Notice the velocity drop?
The brass didn't change in weight, and your chamber certainly didn't vary in volume. The only thing you changed was case volume.
This shows that brass weight and case volume do not directly correlate, and there is no math that would.

You either measure prepped & fully formed case H20 capacity, cull what departs, and control capacity with a sizing plan, or you do not actually know if your cases match.
You can be content with that, rationalize it away, but you can't deny it until you've at least measured it.

Topic: Case Volume (Read 853 times)
http://forum.accurateshooter.com/index.php?topic=3781519.15

In the photo below Lake City cases are on the right and left and a Federal case in the center. Now take a guess necchi and tell me which weighs more, the Federal case or the Lake City Case?

 

[necchi]

Sorry jack, pointing at pictures is all you do, getting you actually grasp the concept beyond 8th grade science is a hopeless cause, many here have tried.
When you can't understand, you force your logic by pointing at more pictures then make jr high jokes at and of people.
Your an absolute waste of time and band width.
I'm not going to waste my time with you any further, sorry I don't wanna play.
Now have the wifey mix you another hot toddy and go play with your picture books and fun bullet making loading toys.

 

[bigedp51]

Dear necchi

I understand your pain and anger, not winning any local, regional or national matches with your H&R Handi-Rifle that shoots dime size groups at 200 yards must be pure anguish and causing all you anger.

I have a NEF Handi 223 that'll make dime size groups at 200.

 

[37Lincoln1]

Nice article about case weight/capacity. Dmoran did a lot of work, pretty pictures and everything too.

http://forum.accurateshooter.com/index.php?topic=3807856.0

 

[bigedp51]

The OP question is below, his brass isn't from the same lot and is range pick up brass. He is also asking if he can use the same load he used in the mixed Remington cases with his mixed Lake City cases.

There isn't enough winter left in ND to test 500 mixed brass cases, and how many of you swap case manufactures and use the exact same load?

I am reloading for my AR-15 which is chambered for 5.56 NATO/.223. Recently I bought about 500 once fired casings with .223 and 5.56 casings both mixed in. I sorted all of the .223 casings out and have only been using them. I want to use my 5.56 brass with the same load I have in my .223 casings but I have read that the 5.56 brass is slightly thicker and therefore reacts to loads differently than .223 casings do. Is there any truth to this? And if it is true, is there any way to figure how much less powder to use in order to get it to be the same as my load in .223 casings? Any info would be appreciated. Thanks.

The OP answer is on the home page of AccurateShooter.com

"From a reloading standpoint, the important thing to note is the rather substantial variance in case capacity from one brand of brass to another–as much as 2.6 grains! So, you cannot assume that a particular “pet load” will work if you change brass brands–you’ll have to do new testing. Whenever you get a new batch of brass, you should measure at least a half-dozen to get the average actual H20 capacity. Compare this with your other cases. You may need to add or subtract powder to maintain a given velocity. Or, if you are already at max pressure levels, you will have to reduce the load if your new batch of brass has less capacity."

223 Rem + 223 AI Cartridge Guide
http://www.accurateshooter.com/cartridge-guides/223rem/