My son has a Browning in 223wssm, and we load for it.
This cartridge is hard on brass, usually we get 3-4 loadings per piece, then we get a crack in the neck. I will anneal the brass and see if we can improve on that.
It is a speed demon. Hornaday manual says they got 4,600fps with a 40gr Vmax.
We load a 60gr Vmax at 3,700fps, and it is a hammer on coyotes. I shot a coyote with it at about 180yds, and watched a large piece of coyote fall back to earth. At first, I thought it was a bird falling out of the sky, until I got there and found the coyote chunk.
Powders like 4350, 4064, RE15, are good places to start with 40-55gr slugs. If you shoot heavier bullets, switch over to RE19/22, 4831, etc. to get great speeds. Magnum primers are what we use.
My son first had a Winchester Super Shadow in 223wssm. It was the most inaccurate gun I had ever come across. My notes say 2 on paper, 3 off, at 100yds, with many different combo's. The bets load I found for it gave 2" groups at 100yds. He then traded it for the Browning, which shoots great.
I recall reading that someone borescoped a Winchester wssm barrel and found the chrome lining to be highly inconsistent, with bare spots showing.
My advice? Shoot the gun before you buy it.
