Appears Sig has some problems with the hammers in their 2 stage triggers. Not properly heat treated.
https://www.ammoland.com/2017/09/si...l-notice-limited-number-rifles/#axzz4su6bOLve
https://www.ammoland.com/2017/09/si...l-notice-limited-number-rifles/#axzz4su6bOLve