A little while ago I built a custom saddle for a chap who needed one for a Remington 597. The 597 is an autoloading .22LR with a very odd shaped magazine.
As you can see, the magazine doesn’t lend itself to the usual style of magazine pouch so I had to come up with something a little different. A variation of the 10/22 pouch did the job. I used the same basic pouch design but replaced the internal web with elastic, to stop the mags from rattling about in there.
While the 597 pouch is not currently in the web store, I am happy to make one if anyone needs one, just drop me a line and let me know.