Isn't that what circlips do best? Perhaps you are misunderstanding 'circlip' ?

The stainless will give out before the circlip does unless you are using some fancy grade.

Could you replace the end spigot with a circlip?

Do you really need stainless?

If you could use a 20mm linear rail with two circlip grooves cut in it... concentricity ceases to be a problem, the circlip grooves will not deform under load, you get a perfect fit in your bearings and the whole thing will be more rigid.