Brass

[Keystone19250]

This is a question I’ve been wanting to ask for awhile, is there a difference in brass between manufacturers and or calibers? The reason for this is I’ve noticed that no matter the manufacturer the 5.56 is discolored in the crimp area of the round but I don’t see that in other calibers. To you guys that re-load and I’m sure most of you this may seem like a stupid question.
Below is a picture of 4 different calibers.
Left to right.
.308, 6.5CM, 300BO and 5.56

 

[Talyn]

It's annealing.

Some manufacturers polish it out & others don't.

 

[Annihilator]

Ok, the discoloring around the neck is caused by annealing the case neck, this is usually done on once fired military cases, and to answer you question on difference in cases from different manufacturers is yes, some are thicker, some the web area inside case is different, even though you have 2 cases from different manufacturers in the same caliber, there is is difference between them, this is also for handgun cases too.

 

[TEXASforLIFE]

It's a military requirement! They don't want the polished ones!

 

[TEXASforLIFE]

Here's a few and the red/black box is 222rem for reference. The lonely one is Winchester white box .

 

[TEXASforLIFE]

Your 556 must be 55fmj!

 

[Keystone19250]

Here's a few and the red/black box is 222rem for reference. The lonely one is Winchester white box .View attachment 4748

Your 5.56 from PMC looks polished?

 

[Keystone19250]

Your 556 must be 55fmj!

Yes.

 

[SMSgtRod]

You can even find a manufactures difference in primer size. (small vs large) 45ACP

 

[Keystone19250]

You can even find a manufactures difference in primer size. (small vs large) 45ACP

I’ll admit never looking at that.