I looked for a 220 Swift at the Leupold website, but there is on scope with that name.
So, I thought you meant that you placed the 6 inch sunshade directly on a rifle in 220 Swift caliber. For the life of me, I can't figure out why you would do that, where you would place it, what function if would serve, how you would attach it (Duct tape?) and why you would sell it on the gun.
So, I'm coming to my third iteration and I think you're trying to tell us that you had a scope on a rifle chambered in 220 Swift and that scope have a 6 inch sunshade.
So, if you're looking for a 6 inch sunshade, why don't you get two 3 inch sunshades and screw one into the other? That will give you a 6 inch sunshade.
Now, if there's a scope involved here somewhere, it would help us if you told us what it was.