I bought a large amount of brass on AR, WW..
I noticed it had a O stamped on the case body, something I had never seen before and it was a tad bothersome...I started checking into it and found it was fired by Win.at there range for various reasons and quite safe to reload..It is excellent brass and only fired one time,..Good stuff btw..

Just one of those little facts we seldom hear about and of no great importance..

that little 0 could be from where the transducer sat for the pressure test of them working up a load with a new lot of powder.

I know you can get 410 cases from Remington with that same little circle indent.

nuthin wrong with it, they weren't proof loads, just test bed cases.

Exactly!

I do not know how you can say Winchester and good brass in the same sentence.

I have a ton of shotshells that I brought from Precision Reloading that have that mark- pressure testing as others said.

(they are remington 12 ga 3.5" hulls)

Chuck Nelson,
I know of no better brass than WW, been using it for at least 75 years..as have millions of folks on this side of the pond..Same goes for Remington..I also like starline, PPU, RWS, the only bad brass I know of is from Australia, and its good enough for the old winchester rifles of yesteryear..Ive tested it all, most is just fine..the rest is BS..

There is a person on 24 Hour Campfire that sells this brass weekly in various calibers. It's a lottery draw....If you are on when she posts it you have about 10 seconds to decide or somebody else will scoop it up. Usually sells it in lots of 200-500 in various calibers. I've use a lot of it in 223 and .222 caliber with no problem.