I'm thinking about putting one on my 580 series 'Mini.  Are they any help or hindrance on the accuracy?

Thanks!
TheMULE

If its anything like the ones that came on the remington 700 then NO.  Unless you like your stock to be like a wet noodle.

I love Hogue grips and the shotgun forends and stocks but not on a rifle.

Suggest you take the money and first buy decent cleaning supplies/tools (most definitely including a Muzzle Guide) and some ammo.

Shoot the thing with as many different types of ammo as practical and take good notes while you are zeroing it in.

What you want to do is verify 100% functionality and reliability while breaking-in the Mini.  In the unlikely event you need to send the Mini back to Ruger, you will need to remove all user-done mods.

I have heard a few folks comment that the Hogue stocks felt objectionably "sticky" to them, particularly in hot weather.  YMMV, of course.

Unlike most "hard plastic" syn stocks, the Hogue "overmolded" Hogue stock may be incapable of being painted.

Depending on the fit of the stock (any stock) to the barreled action, some "shimming" of the inside of the stock, using thin incompressible metal shims can often "tighten" things up.  This is a common "trick" amongst many rifle owners, and Mini owners also.  Many wooden Mini stocks are notoriously of "loose" fit; syn stocks usually "tighter" but may also benefit from shimming.