"Commercial" vs "Military" LC 5.56 Brass

[Phylodog]

I'm preparing to load for my .223AI and have a question about LC brass.

I probably 5000 pieces of once fired LC marked brass (fired through AR15 rifles) which was packed in Federal American Eagle 55gr ammo. It has the Nato cross in the headstamp as well as "LC" and the 2 digit year. It was crimped but not annealed.

I have also fired some Federal XM193 through my rifle to form the brass and it has the same info on the headstamp but it is oriented differently, it is crimped and also annealed.

Are there any differences between these two which would prevent me from using both for reloading? I understand that with different years I may get difference velocities but I'm wondering if there are any differences aside from lot variances?

Anyone know?

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

1 - Check weight
2 - Check neck thickness

Some swear by annealed brass, I have'nt seen no measurable diff. Annealing will make it harder but can also make it more brittle. The faster the brass conforms to the chamber during firing the better and strighter the release of the bullet.

 

[chuff]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ltfirehunter</div><div class="ubbcode-body">1 - Check weight
2 - Check neck thickness

Some swear by annealed brass, I have'nt seen no measurable diff. Annealing will make it harder but can also make it more brittle. The faster the brass conforms to the chamber during firing the better and strighter the release of the bullet. </div></div>

Shouldn't annealing make it softer?

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

Annealing makes it stiffer or harder like any other metal, the right amount of heat and cooling procedeure is the key.

 

[Bacarrat]

Re: "Commercial" vs "Military" LC 5.56 Brass

Wrong. Annealing makes the brass softer. And with brass you can not make it harder by heating it. It must be worked to make it harder.

As for LC brass. Load it up and go. LC is about as good as it gets.... except for Lapua.

 

[chuff]

Re: "Commercial" vs "Military" LC 5.56 Brass

From wikipedia (I know, not the best source):

"Annealing, in metallurgy and materials science, is a heat treatment wherein a material is altered, causing changes in its properties such as strength and hardness. It is a process that produces conditions by heating to above the re-crystallization temperature and maintaining a suitable temperature, and then cooling. Annealing is used to induce ductility, soften material, relieve internal stresses, refine the structure by making it homogeneous, and improve cold working properties.

In the cases of copper, steel, silver, and brass this process is performed by substantially heating the material (generally until glowing) for a while and allowing it to cool slowly. In this fashion the metal is softened and prepared for further work such as shaping, stamping, or forming. It also presents no problem with decarburization."

Definition of "anneal" from Webster's online dictionary:

1 a: to heat and then cool (as steel or glass) usually for softening and making less brittle ; also : to cool slowly usually in a furnace

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

PLease pardon my ignorance had it backwards

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

This was embarrassing, I talked to my friend that done metal treating for years and I was way off base with my answer and I just got it backwards. And I do apologize to Phylo and others.

 

[former naval person]

Re: "Commercial" vs "Military" LC 5.56 Brass

According to sources, all factory brass is neck annealed after forming. The military requires the discoloration from annealing be left on and not polished off like the commercial "sales appeal" stuff. That way, visual inspection can verify that part of the mil spec procedure was accomplished. Lapua for instance, doesn't polish it off so you can see the annnealing colors.

 

[Phylodog]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">According to sources, all factory brass is neck annealed after forming. The military requires the discoloration from annealing be left on and not polished off like the commercial "sales appeal" stuff. That way, visual inspection can verify that part of the mil spec procedure was accomplished. Lapua for instance, doesn't polish it off so you can see the annnealing colors. </div></div>

Had not heard that, I guess that's one less difference between the two types that I have.

Thanks for the information guys,

Don't sweat it Chris, no harm - no foul.

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

Thanks man , I just got it in my head and it stuck. I appreciate the guys here getting it straight for me. After I talked to Johnny last night I figured out why my feeble mind got confused about it.
Thanks guys

 

[Grump]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: ltfirehunter</div><div class="ubbcode-body">Thanks man , I just got it in my head and it stuck. I appreciate the guys here getting it straight for me. After I talked to Johnny last night I figured out why my feeble mind got confused about it.
Thanks guys</div></div>

Thou art too friggin' humble, man.

A feeble mind would NOT have gotten it.

I'm trying to teach/convince my kids that there's a BIG difference between dumb and uninformed. One can be fixed easily, the other requires more work and maybe even work-arounds...and even then there is sometimes a limit.

 

[ltfirehunter]

Re: "Commercial" vs "Military" LC 5.56 Brass

My father always told us to admit your mistakes and then learn from them. I am not to proud to admit when I'm wrong. What I done for 25 yrs. sometimes had the tendacy to humble you.

 

[Tylermtech]

Re: "Commercial" vs "Military" LC 5.56 Brass

I really like LC brass, I sort it by year and load it up. Some say that you will have more incomplete fireforms (weatherby style shoulders) with military brass, but it seems about the same to me.

 

[johngfoster]

Re: "Commercial" vs "Military" LC 5.56 Brass

Correct me if I'm wrong, but heat treating steel hardens it (heating it up then cooling it rapidly). If you want to soften it you need heat, then cool it extremely slowly, over a period of hr or days. Brass softens with cooling much quicker. I'm no expert, but this is how they harden steel for knife blades. This may be where some of the confusion stems from.

 

[montyb]

Re: "Commercial" vs "Military" LC 5.56 Brass

heat treating is a general term that can include tempering and annealing. tempering steel is hardening it, and annealing it softens it to the degree you wish. you can temper a knife blade so it would break like glass, and anneal it to make it soft enough to be tough.

 

[Tylermtech]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: johngfoster</div><div class="ubbcode-body">Correct me if I'm wrong, but heat treating steel hardens it (heating it up then cooling it rapidly). If you want to soften it you need heat, then cool it extremely slowly, over a period of hr or days. Brass softens with cooling much quicker. I'm no expert, but this is how they harden steel for knife blades. This may be where some of the confusion stems from. </div></div>

your on the right track, but you don't need to cool most hardened steel slowly to soften it, just heating it up will soften it up. The reason that this happens is because in the original heat treatment, when the steel is cooled, it is cooled rapidly enough to form martensite. when you heat the steel up, it has a phase transformation to one that is not as hard as martensite.

When you heat and cool brass/copper.. the grains grow, but there is no phase transformation upon cooling to make the brass harder. As stated above, the only way to harden brass is to work harden it. When you work harden metal, the grains are compressed and the dislocations are restrained, and this makes the metal resistant to deformation. Annealing causes the compressed grains to enlarge/combine and relieves the internal stresses that led to the work hardening.

There are of course exceptions to the above statements, YMMV

 

[Two Shoes]

Re: "Commercial" vs "Military" LC 5.56 Brass

+1, ALL CF rifle brass is Annealed..................

 

[shepherm]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: former naval person</div><div class="ubbcode-body">According to sources, all factory brass is neck annealed after forming. The military requires the discoloration from annealing be left on and not polished off like the commercial "sales appeal" stuff. That way, visual inspection can verify that part of the mil spec procedure was accomplished. Lapua for instance, doesn't polish it off so you can see the annnealing colors. </div></div>

I don't know that it is required by the military, but it cost less for them to not polish the brass. All brass I know of is annealed at some point because the brass is to brittle and will split the neck if not.

When you heat metal and cool it fast you temper it, which makes it stronger but brittle. If you heat metal and cool it slowly it makes it softer and more flexible (less brittle).

 

[Tylermtech]

Re: "Commercial" vs "Military" LC 5.56 Brass

You cannot harden brass by heating and quenching

 

[shepherm]

Re: "Commercial" vs "Military" LC 5.56 Brass

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Tylermtech</div><div class="ubbcode-body">You cannot harden brass by heating and quenching </div></div>
This is true I should have put steels/iron not metals. Brass does not have the carbon in it that is need to temper it and make it harder. Thanks for pointing that out.