The last time I was in the store, Del Selin's in Vernon BC had some new brass on his shelves. If you ask nicely, he may even have some older Remington made boxes of 20 in the back room. 250-545-6413 Tue - Sat 9-5 PST
I really like the 357 Maxi and have a couple of Maritnis chambered in the cartridge. One has a 1-18 twist rate and is used for Hornady 158 to 180 grain bullets.
The other has a 1-10 twist rate and I load it with 250 grain Hornady spire points and round nose bullets. This round with heavy bullets is very surprising. Just below sub sonic speeds. It is a perfect tree stand rifle or for areas where short range shots are the norm.
One thing though, at 200m the 250 grain bullets will penetrate a 10in pine log and keep on traveling.
Both rifles also really like cast lead.