I purchased two of this companies 597 magazines, and find them to function perfectly in my one remaining 597 .22LR.
http://www.keepshooting.com/remington-597-magazine-10-round.html

They are heavier than the Remmy mags, and feed flawlessly in my gun, which has a Volquartsen extractor installed. With the Rem original extractor, nothing fed or ejected well. I can only get 8-9 rounds in them though for some reason. That doesn't bother me though; they feed perfectly. I will try polishing the insides when time permits, to see if I can get a full 10 rounds in.

I also have a 30 round Rem magazine, and it feeds and ejects spent rounds flawlessly with Federal cheapo ammo, Rem cheapo, and CCI cheapo. Can't do much better than that, but I attribute the flawless performance to polishing the guide rods, chamber mouth rounding of the lower edge, and the VQ extractor.

The Rem extractor was junk! My other 597 was iffy on feeding and ejecting, but I never tried a VQ extractor in it. It had the type one mags though, and even after polishing them, it still was iffy for feeding and extraction. Go with the VQ extractor!

Thanks for the info; always good to know where to source additional magazines. Let us know a long term update as well if you don't mind.

Welcome to the Remington Owners Forum gunsmither !!

FYI, they do NOT make a 22 WMR version for the 597's.

Sadly my experience with these isn't all that great. Bought two in Dec, '18 and one in Jan '19. The newest one after a mere 40 rounds no longer holds the bolt open after the last round. I contacted them after returning from the range and have not heard back, been a week now. Nothing stands out as to be the problem, the other mags I have continue to operate even when the problem mag does not.