IMI .223 ammo

[foxx]

I am just now getting around to putting together my first AR-15. Not a big fan of them, but figured I'd better get one while I still can.

Since I started handloading a few years ago, I've never bought any factory ammo, but I guess I might for the AR. I never paid any attention to this sort of thing before. IMI is pretty inexpensive ( for cartridges ), is the brass any good for reloading?

[Robinhood]

Good enough. Israeli Military Industries

[earl39]

Yep good ammo and brass

[The Old Coach]

I've never ever had bad ammo from IMI. I do point out that 5.56 brass I've had from IMI was heavier than LC or typical US-made commercial, so loads may have to be adjusted downward a smidgen. Assuming that you reload at all.

[bc83]

Y not hand load

[foxx]

I plan to, but at $.41 a round, I figure i can have some fun with factory stuff first, then reload.

[Don-T]

Lot of guys, like me, prefer IMI brass for reloading. It and LC are the best (IMHO) for forming into other stuff like .20 TAC and .20 Vartarg.

[darkker]

IMI was producing brass for "winchester" branded stuff fairly recently. Remember that case weight isn't singularly indicative of volume. There are many different case alloys and brass formulas. Unless you know what alloy and formula is being used, weight MAY, or may NOT mean capacity is different.
There are several chambers offered for the private sector, but if you look at offical SAAMI drawings and CIP, the difference in 5.56 and 223 is ONLY in the throat. Some, such as Savage, have NATO length throats in the 223 chambers.
Also do not buy into the notion of "The pressures are different", argument; at best it is semantics.
Jump to CIP and take a peak, they are the same pressure ratings.
So why the "confusion"? HOW and WHERE pressure is measured is different, and they DO NOT corrolate.

[earl39]

Thank you darkker i have been saying that for a while

[bigedp51]

Military Lake City and commercial contract 5.56 made for the military is made of harder brass and has a thicker flash hole web for radial strength.



I buy a lot of once fired Lake City 5.56 brass for its strength and longer reloading life.





How Hard is Your Brass? 5.56 and .223 Rem Base Hardness Tests

http://bulletin.accurateshooter.com/...ardness-tests/

What you have to watch for are softer .223 cases with thinner flash hole webs that cause over sized primer pockets after a few reloadings.



Below the majority of the cases have a similar case capacity, and as you can see the Lake City cases have the most case capacity. But be aware the difference between 28 grains of H2O case capacity and 30.6 can cause 6,000 psi difference.



Below a Lake City case with a case capacity of 30.6 of H20 and a 55 grain fmj bullet and 25 grains of H335.



Below the same load and bullet as the top chart but a case capacity of 28 grains of H20 and 6,000 psi higher chamber pressure.

[darkker]

That's good info Ed, but is missing some important notes.
The base argument about cases is missing important info, even if it doesn't change much in the end. So for the sake of clarity:

I did a post on another board a couple years ago now, specifically about the 223/5.56. Of the true domestic mfgrs, which took a bunch of doing to get a human that could tie his own shoes, They all said the cases are built to the same specs, but get a different headstamp. From a practical standpoint, this only makes sense anyhow. In the the Accurate shooter post from 2014, one of the cases was "Winchester". In 2014 Olin had already sold it's cartridge case production facilities about a decade previously. They have cases built on contract, in a "least-cost" bid method. So to tie that to the general theme, NO ONE tells you what they spec cases to. The last time that I'm aware of that a company publicly published alloys and heat treat specs was Olin in the 40's-50's in the 30-06. They were using alloy C260 which had a spec'd tensile strength of around 75-80,000 psi. Since then it is a mystery. But from another article A.S. published I believe late last year, there indeed are several formulations of brass being used.

Another thing to be cautious of is QuickLoad with any spherical powder coming from General Dynamics. Hartmut gets anything and everything he wants from Eurenco, and prior to the J.V. Thales, and Rhienmetal. General Dynamics tells him nothing, and Hodgdon won't tell anyone anything. From using a Pressure Trace system over several years, there is a VERY good reason why Hodgdon only states that lot variations can be as large as 10%. Aside from that, Hartmut's bomb testing really struggles to accurately describe how most of GD's sphericals actually behave. Hodgdon doesn't do much of their testing in-house, and has limited info on Superformance(one example). In many conversations with them, they don't seem to know that it is extremely progressive, nor how the burning curve changes with Pressures.

H335 and Bl-c(2) originally came from the same parent powder. The difference came on the "As-Built" bases and are different by 0.25% of an acid stabilizer. It took Picatinny several hundreds of thousands of rounds and many years to find "the issue", and it wasn't related to burning curves. They also did a search of the SD of lots of cases from a few different lines of machines. The difference between presses was stunningly large, and the SD from a single lot also larger than was anticipated originally; perhaps a hazzard of churning out a few billion cases a year. So when the 5.56 Nato was born and being ironed out, I have no doubt that cases needed some work as well between the two. But as the world sits currently, think the issue is mostly old legend.

The final component to consider is how things are controlled, and compared against. Remember that charges of powder in Grains, is a reloader thing, not a production ammo thing. What they load is also not canister grade blended powder. The defense contractors order train loads of specific characteristics, and test those lots against the order and finished product. Hodgdon buys rejects, or toll milling time for a few semi's and blends to a generalized burning rate they desire. So the "Nato standards" and the reloader aren't the same animal. Performance numbers may well be mirrored, but the way we get there are two different things.
Also we are the ones who want to re-use brass. The military needs it to last once only.

[Texas10]

Darkker makes a good point about brass manufacturing being a "lowest cost" supplier, and it only has to work once in most cases. Reloaders are the waste market, and those who are makers of reloading expendables, price their components accordingly. But the internet is the ideal rookery for rebirth of old, out of date information and the graphic above is an excellent example. There's an old saying in manufacturing. "Cheaper, faster, better.....pick any two".

After seeing the pictured American Eagle brass sectioned to illustrate case web thickness, I cut some of mine. They all measured .070, same as my new Winchester 223 brass. And the newer brass from AE, meaning THIS year, has much more consistent shaped and located flash holes, exhibiting a clean, cylindrical shaped flash hole punch, and not the bell shaped hole I've seen in last 2014 ammo indicating too much clearance between punch and die in the manufacturing process.

I called Federal and they mailed me a copy of the specs for the AE223GTV, varmint tipped ammo that shoots so well out of my 12FV and 12BVSS.

Case is made of C260 brass.

One thing I've noticed with Federal 223 brass NOT marked LC is that about 25% of the factory loads have brass that is under minimum length by a thou or two. And if you buy a jug of Federal 223 never fired brass, I've found an even greater percentage of too short brass.

So again, reloaders are the waste market, and it may be better to harvest reusables from factory ammo, instead of buying new, supposedly identical supplies. Unless from a custom manufacturer such as Nosler, Lepua, etc.

Even then, I've read some custom brands are really just sorted common brand materials.

Oooops! Did I just give birth to old, outdated information......again?

[The Old Coach]

Case is made of C260 brass.

Something that needs correcting about a previous post. C260 is the ONLY alloy used for drawn cartridge cases. There are no others. Only cases that are machined from solid, such as the Rocky Mountain line of obsoletes, use a different alloy, and that is because you can't buy C260 in rod form from any mill. C260 is supplied in sheets as raw stock for stamping out the blanks for deep drawn parts, (i.e. cases) and also is supplied as drawn wire for parts that will be headed by upsetting or bent up in a four-slide. It is only made at all because the drawing/heading/bending processes prefer it to all other brass alloys.

Wanting to get C260 bar stock for machining obsolete cases myself led me to research this at some length.

[darkker]

Very interesting to hear they are still using the old Olin alloy, wonder what the heat treat spec is...

Since it relates, a side note to Federal for you Texas10.
AT least in the 308/7.62 cases, and specifically the FGMM. One of the "tricks" they have employed for some time to help with their well earn rep for accuracy is very soft heat treat specs. A softer case will obturate much faster and seal the chamber more rapidly. The downside, as it relates to the reloader, is they have been known to get a wee carried away in how far down the case the softness is. The heads can be dangerously soft. Don't think I posted it here, but when fooling with the Pressure trace system we've had lighter loads (50-55,000) that had the heads grow my shocking amounts. Have grown extractor grooves by a tenth!!
Was firing in a hawkeye and XL7. The Ruger dealt with it just fine, but the X7 blew the snot out of the extractor.


I see that one got snuck in before I posted.
That is incorrect, at least on "as-built". You can skin a cat several ways. Here is the article I referenced earlier.
http://www.accurateshooter.com/techn...rtridge-brass/

[Robinhood]

[Robinhood]

Ever wonder why some want brown box Lapua brass. One of the qualities of C280(C28000) is a higher anneal ceiling. It has almost 40% zink and is Is that the reason for brown box preference? I don't know.

C28000

C26000

C24000

[The Old Coach]

I want to see the credentials of of the "lab" (if there was one) who came up with that XRF analysis.

[Robinhood]

The graphic came from AccurateShooter AKA 6BR. Article

The samples I referenced were done an regulated facility where everything has a file and folder with certs and documentation. All material is checked to ensure that no material of inferior specs comes through the door.. I did not look at the calibration data but it was done as every piece of inspection equipment they have is done religiously. The tolerances on the ratios of lead and tin are relatively wide as in 3 -4 percent. 6 cases were tested of different manufacturers and two cartridges. 5.56/223 and 7.62/308. If you are interested in having a few of your brass cases tested PM me and I will see what I can do.

I am assuming that you believe there was some conspiracy in the testing. I hope this helps.

[The Old Coach]

Conspiracy? Well, yes, of a sort. I wrote my first MIL-45208 manual, and the accompanying Mil-45662 manual, in 1978. Second one in 1983 for a new employer. In that case I had to administer the programs as well with my other hand while I did my main job of engineering machine tools. Later I did fifteen years doing process control measurement systems for GM/Ford/Chrysler et.al. So this sort of thing has been my career for about 30 years out of my career. Somehow this magazine story, and the superfluous metablog you wrote around it, doesn't ring true. I will add that "editorial content" written for popular magazines has only one purpose - attract eyes to advertising, or to be advertising in and of itself. It is often fiction that elicits belly laughs from real engineers.

I finally figured out why I keep getting email notifications about this thread, and have turned them off, so that's my final word.

[darkker]

"Real Engineers" like science and testing proof of concepts, and understand there are several ways to accomplish any task.

[FW Conch]

^ What ! ^ It's not directly proportional to the amount of money spent?

Shocking !!! :-((

[Robinhood]

My statements where not meant to be offensive. Did you read the article? Besides exerting your credentials and ability to insult, how do you prove your position that all Cartridge Brass is C260?