I have three rifles that show honest wear from their barrels rubbing against trees and shrubs. While only cosmetic, I want to improve their appearance. Does anyone have any tricks on diminishing those marks?

If they're polished originally, polish 'em again.. If they were of a 'dull' finish, a proper bead blast will remedy any mark..

All of my SS rifles have "character marks"

Redneck has the idea and the experience. Or bead blast it and apply a hard finish. Be Well, RZ.

Mine are bead blasted (sako’s) so every so many years I jus touch them up.

The Sako’s use a REALLY fine (almost powder if it’s not powder) grain of glass beads.... that is if I want it to match the finish of the reciever perfectly..
But frankly any grain bead blast is so close no one notices...

I’m a bit on the accuracy OCD side so if it can be beyond perfect I will probably waste extra time trying to getting it there
the obvious way is to blast both the action & barrel will get you there anyway...

While a highly polished stainless barrel may look nice, for a while, it doesn't last long. Even a benchrest gun will shows marks at some point. A dull matte finish doesn't mark up as bad. Wrapping the barrel with a scotchbright pad and working it by hand is something you can do yourself to maintain the look.

pro-shot makes a cloth for stainless guns, I've made pawn shop finds look almost brand new with them.

https://www.proshotproducts.com/Lead-Clean-Cloth_p_603.html

then I follow up with their metal care cloth.

Thanks for your replies!

I use Mr. Clean "Magic Eraser" original on minor marks and Mr. Clean "Magic Eraser" extra power on some stubborn marks.

I agree with Wayne, I've used a ScotchBrite to even up the surface on a couple stainless barrels. The Burgundy colored ones are less aggressive and that's what I prefer. Available at the local paint store.

I just bead blast again

Just follow this long time member's regimen and you'll never have another problem with SS.