I have a Remington model 600 in 350 mag. I've taken whitetails with it and it has worked great! But, it's more of a collector & a fair weather rifle than a go to rifle for me.
I've handloaded 350 mag ammo for a friend that I'm going moose hunting with in Newfoundland in less than a month. The load uses a Barnes 180 TTSX flat base bullet at 2810 fps according to my Lab Radar unit. His rifle is also a Model 7 Custom Kevlar with a 22" barrel. I'm excited to see it perform!
I also had a Remington Model 600 in 350RM. It was an absolute BEAST to shoot and delivered more punishment to the shooter than the game. LOL
That was the only rifle I had stolen that I didn't miss back in 1986.
About 15 years ago I replaced it with a Model Seven KS in 350RM with the Brown Precision stock and a custom barrel with brake. It's also a beast to shoot but bearable if you wear double hearing protection.
Anyway my Model 600 was used to dispatch a few elk that were wounded by hunters when I worked for an outfitter in Colorado and a few of my own when I had the time to hunt and it was quite adequate for elk. I liked it because it was short handy and very powerful but sighting it in was always very unpleasant.
I know I used factory ammo for that 600 but for the life of me I can't remember what it was but I suspect it was Nosler Partitions as they've always been my favorite bullets for close encounters (under 200yds).
Anyway. I highly recommend the Model Seven KS in 350RM for medium to large and dangerous game if you want a light, short, and handy rifle that has the punch to kill the big nasties in short order it's your huckleberry.
You'll probably want to handload for it though because finding factory ammo in a pinch might be nearly impossible and you'd surely pay through the nose for it these days.
*** EDIT *** I just did a search for 350RM ammo and Ammo Seek showed NONE anywhere and if you're willing to pay about $5 per round you can get some old Remington factory ammo on Gunbroker. Brass is just as expensive. I guess I could get rich selling some of my brass. LOL