I never had a problem finding 6.5x55 ammo locally. And I've also found it easily online from Grafs and AIM Surplus as well. I think Prvi is still making production 6.5 ammo also. I'll agree it won't be as common as mainstream calibers, but it's not exactly scarce either.
I like the fact that the 6.5x55 performs better in the field than it would appear on paper. It is about the mildest recoiling deer caliber I've ever shot and it's unique. I really enjoy the round.
+1.