Difference-"Win-USA","Winchester" & "Win"

If I recall correctly, the newer 5.56 is partially(possibly all?) manufactured at Lake city, since winchester now runs LCAAP.

For basic plinking, I would just pick a middle of the road load and load up all of them. If you really want precision, you'll have to check each stamp on their own.

I would weigh them and see if they match. Volume is not directly tied to weight because of different materials used but in this case the belief is there all from the same plant so correlation is strong. If there all inside a grain maybe two it's close enough

A few months ago I took 5 random cases from several headstamps, weighed by empty case and added water. All cases were resized and a spent primer inserted backwards. All cases were trimmed to 1.743".


Of a 5 case average, Winchester weighed 29.9 gr. Win USA weighed 30.2 gr. These were water weights.

I don't believe it was enough to matter, as I saw no spike or drop in all the cases I weighed. Spreads were no more than .4 gr. on any of the various cases that were selected.

gifbohane said:

Thanks for the replies..

My main concern is where were these headstamps made? USA? All made by WInchester?

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I wonder if it has to do with the brown box they came out with recently.

https://winchester.com/Products/Ammunition/Rifle/USA/USA223LKY

Brown boxes because the industry ran out of white..