Salem

I was wondering if anyone would know why the iron bars I bought off a player went missing then today about a week later came back on the ground near my base

The iron bars were on the ground and not in a container? Items that fit in your inventory will all disappear after a certain amount of time (usually between a few minutes and an hour or so depending on the item) so keep all items in a container. If you did have the items in a container and not on a claim then someone probably found them and took them. It's not stealing if they don't take it off of a personal claim

troubleis wrote:Items that fit in your inventory will all disappear after a certain amount of time (usually between a few minutes and an hour or so depending on the item) so keep all items in a container.

This reads a bit misleading. What he means to say is items that can fit in your inventory, and are placed on the ground, will despawn after a period of time.

I had them in a box and I went to get them out of the box they weren't there and then today I found them on the ground

Sounds to me that you didn't have the box on a claim and the box decayed and dropped the contents onto the ground. All items should be kept on a personal claim

no I had them in a box and I had my area claimed

TwiztidJay wrote:no I had them in a box and I had my area claimed

Does you claim still have silver in it?

at the time the claim did have sliver it doesn't now we have made it a town and taken down all are personal claims

Perhaps someone ran up to the box, stole the iron, logged off. Then, later, in an attempt to port home without KOing they dropped the iron on the ground and you happened to find them before they decayed.

Possibly you had a theft? Turn on tracking in Adventure > Toggle Tracking then you need to enter a house or mine or port to Boston and back. Then search your property for a pink exclamation point.
EDIT You said WE, so it sounds like maybe someone else in your town moved them