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How rare is a 116?
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FWIW, Here in the USA Ive seen three (two 12 gauge guns and one 16 gauge gun) come up for sale in the last five or six years.
Youre right on target about dealers swimming in used Spanish side lock shotguns, but those guns are mostly lower price point or entry level guns. At any given moment theres lots of AyA No. 2, Garbi model 110, Arrieta model 577, and UA model 210 shotguns looking for a buyer. Which is because those guns are, in the context of Spanish side locks, priced were a lot of people can afford them and have bought them.
The Ugartechea model 116 is a horse of a different color. Thats a gun at a price point similar to a Garbi 200, Arrieta model 872, or Grulla Holland. These model guns do come up on the used market occasionally. And when they do they tend to sit a long time before selling, because very few people are willing to spend that much money on a shotgun.
I was watching the auction for Claychrushers IU model 116 and he got one very nice deal, paying a thousand dollars less than the least Ive ever seen an IU 116 go for before now.
Kudos to ClayCrusher.