THE COPPER SCROLL is the subject of an essay by Robert R. Cargill at the Bible and Interpretation website: "On the Insignificance and the Abuse of the Copper Scroll." Excerpt:

Scholars aren’t quite sure what to do with the Copper Scroll. Milik concluded the Copper Scroll was placed in Cave 3 around 100 CE, after the other scrolls were abandoned in the other caves. Others like Lancaster Harding and Cross believe the Copper Scroll to be the folklore of Qumran. Still others believe it describes actual treasure belonging to the residents of Qumran. I join the scholars who conclude that the Copper Scroll describes articles from the second Jerusalem Temple (most likely legendary) supposedly hidden after its destruction in 70 CE, in keeping with later date of its composition. The Copper Scroll was most likely placed in Cave 3 long after the rest of the Dead Sea Scrolls were placed in their respective caves. And while it was discovered during the excavations that produced the Dead Sea Scrolls, the Copper Scroll should not be considered part of this collection because its author(s), script, style, language, genre, content, and medium are otherwise unattested among the Dead Sea Scrolls.

Because of this irregularity, amateur treasure hunters and even some scholars regularly appeal to the Copper Scroll in a seemingly perpetual effort to promote sensational fringe theories, raise money, and bring attention to their far-fetched claims. Sensationalists prey on the ambiguous and everyone loves a treasure hunt; the Copper Scroll is both.

There follows much entertaining debunking.

I think the Copper Scroll is a genuine (i.e., not legendary) list of treasures, perhaps treasures associated with the Temple. I have more on the Copper Scroll here (follow the links back) and here.