This thread should have been titled "Look what I brought home!".....with pics of course. It is an efficient cartridge that should still be offered by manufacturers IMO. I think Ruger is the only one still offering it in their No.1. Damd belted magnums killed it off, I think. Been looking for one myself. Buy it!
The only cartridge currently available in the Ruger #1 is 7x57. And I don't think they will make them too much longer. There will soon be no more #1's made. Now the used market is a different story. Used (I prefer pre-owned) #1's are out there and available and will be for quite a while. One good thing about used #1's is that most of them were taken good care of. A guy who owns a Ruger #1 is a serious rifleman who appreciates quality and good looks and doesn't care about (or need) a fast second shot. A .300 H&H in a Ruger #1 should not be hard to find. The .300 H&H was also made by Remington in their M721 and I see those available from time to time.