As I was sorting and cleaning brass I shot and picked up at the range Sunday, I noticed that my Winchester brass felt lighter in my hand than my Hornady brass. Now, I had read on here that the Winchester brass is known for having higher case capacity, which comes by having lower case thickness in the head and elsewhere, so that was no surprise really.

I noticed I was culling a lot of Winchester brass for being blown out of dimensions, as measured with my 308Win Wilson case gage. That extraction process on an M14 is quite violent.

So I decided to take a couple measurements.

I have 4 kinds of 308Win brass on hand:
-Lapua, unfired, unsized and untrimmed. Basically, brand new in the box.
-Hornady 308Win, once fired from commercial ammo. Decapped but otherwise not prepped.
-Hornady 308Win Match, once fired from commercial ammo. Decapped but otherwise not prepped.
-Winchester 308Win, once fired from commercial ammo. Decapped but otherwise not prepped.
Oddly enough, the Hornady match brass came from American White Tail hunting ammo and the Hornady 308Win brass came from Hornady match ammo



I weighed 10 cartridges of each kind.
-The Lapuas weighed between 172.4gr and 175.2gr, a spread of 2.8gr, and averaged 173.95gr.
-The Hornady 308Win weighed between 164.8gr and 168gr, a spread of 3.2gr, and averaged 166.14gr.
-The Hornady 308Win Match weighed between 166.9gr and 168.6gr, a spread of 1.7gr, and averaged 167.63gr.
-The Winchester 308Win weighed between 157.8gr and 161.3gr, a spread of 3.5gr, and averaged 159.26gr.
Note: It would be interesting to see what the Lapuas weigh, spread and average after being sized and trimmed to length. I will do this later tonight I think.

The Winchester brass weighs a whopping 6.88gr less on average, for the brass measured, than the closest brass, the Hornady 308Win.

From the 74 Winchester cases I picked up, I discarded 9 for not fitting in the case gage, a rate of 12.2%.
From the 42 various Hornady cases I picked up, I discarded 1 for not fitting in the case gage, a rate of 2.4%.

It will be interesting to see how many loadings I can get out of the Winchester brass versus the Hornady brass or the Lapua brass.

So what does the Winchester brass I discarded weigh?
They weighed between 159gr and 161.2gr, a spread of 2.2gr, and averaged 159.93gr. That average is higher than the average for the 10 good cases I measured. The spread is less than the 10 good cases as well.
Now the samples are pretty small, so I don't think we can draw particular conclusions as to why they were blown out of proportion, whether it' because of a difference in the timing and the force of the extraction, if it is due to being too thin in the head area or if it's a weakness in the metal of the particular cases.

That being said, I think it's fair to assess that the Winchester brass might be a bit weak for hard-cycling semi-autos such as the M1A/M14. At the very least, you will probably cull more cases than other, thicker/harder brass.

Well, back to loading cartridges for the weekend.

Case weight is not an accurate measurement of case capacity.

See here, although this is 223/5.56, same principle can apply.

http://www.6mmbr.com/223rem.html


You described you brass as "decapped" and not prepped, correct.

Are you actually discarding fired cases that do not fit a case gauge before Full Length sizing?

If you are full length sizing, why not adjust your FL die so they do fit the case gauge?

I just don't want to work the brass too much and weaken it, so I discard it. The cost of a case is low, the value I attribute to my face isn't. Just me being chicken shit.

One should NOT expect a fired case from a semi Auto to fit a case gauge.  You will not over work the brass if you set up your FL die correctly and you don't load them to many times.

Brass can be hard to find, if you are still chicken shit, do not discard, I'm sure someone here will be glad to take it off your hands.

To be clear, most fit pretty good.

These I keep



These I discard

Any 308 brass that you discard, send this way.  I have no issue using brass that I pick up on the range and full length re-size.  I do not expect any of my fired brass to fit in a case gage before it is re-sized.

Right you are, that is why they make Full length sizing dies.  If the sizing process was dangerous we wouldn't be doing it and die manufacturers wouldn't be making them.

None of my fired brass from AR's or pistols fit case gauges before resizing.

Meh. If I was in the States, I'd gladly send the brass to one of you all. I hate jail, though.

Its just scrap metal! It'll be fine