Of the 6 guns of this type recorded as having been fielded with Coronado's expedition, 3 are known to have been found: 2 in Deni's excavations and another in the hands of, I believe, the National Park Service. The gun covered in the Rifleman article was the first Deni found, and is the best specimen. Her second find, while essentially identical, was burst in service, and inspection shows flaws in the casting as the probable cause of failure. The third, which I have not seen, is said to have been purposely destroyed by being externally beaten and deformed - this gun is not currently on display. Both of Deni's guns were featured in presentations by her and her co-author, Bill Mapoles, to the membership of the Historical Arms Society of Tucson, AZ (HAST), of which I am also a member. Many of the other artifacts she recovered were also exhibited. It does appear that the guns were cast in the New World - they are crude by comparison with existing European specimens of similar type, and were quite obviously cast in a horizontal, rather than the conventional vertical, position. As to boring after casting: the crude nature of the guns makes it difficult to tell whether they were fine bored or simply left as-cast - further inspection may clarify the point. That, and the obvious lack of sophistication in their manufacture, make it unlikely that they were produced by the experienced founders of Spain. As to the metallurgical analysis of the bronze, which might tell more about the origin of their substance: I did ask Deni about the origins of the copper and tin in the alloy, and she said that she intends to have the analysis done, but has not yet done so. Native copper was available in the Americas, but the tin in the alloy would almost certainly come from Europe. Casting, while done in an odd manner, would not have been beyond the ability of the Spanish then residing in the Americas, considering how much looted gold and silver had already been smelted, melted and cast for shipment to Spain. And lead, in the quantities needed for Spanish firearms, could have been, and likely was, imported.
Another issue for the Spaniards in the New World, made evident by other artifacts recovered in the Coronado sites, was their lack of non-imported iron, as many (apparently all) of the recovered crossbow bolt points were rather crudely made, not of iron, but copper.
In all, Deni's work has provided a window into the historical events and conditions surrounding the Coronado expeditions, and in the Spanish conquests in the Americas.
mhb - MIke