I've owned one Arrieta 557 and two AYAs, a No 51 and a No 4 Deluxe. They were all bought used. No mechanical problems with any, but both AYAs' barrels didn't shoot to the same point of impact. I owned the No 4 first and couldn't understand why I kept missing easy straightaway shots with the right barrel (It was a true left hand gun. The left barrel was more open.) After I patterned it, I discovered that the right barrel shot 8" to the right at 20 yds, and more apart at longer ranges. I disposed of it. About 10 years later I bought the No 51 and discovered that it was a right hand gun with left hand dimensions. It shot about the same amount apart as the No 4. I don't know if the barrel regulation was by design, but I couldn't shoot either gun because of that.
