He is not supportive of 2A rights. Some examples:
- Antonio Named a Moms Demand Action “Gun Sense Candidate”
- Rep. Antonio Delgado Applauds Passage of H.R. 8
- Delgado Joins Moms Demand Action for Conversation on Commonsense, Bipartisan Measures to Address Gun Violence
- Moms, Delgado: Responsible gun ownership route to curbing violence
- Rep. Delgado calls GOP inaction on gun control ‘naked corruption’
So his appointment does not make anything bettor or worse for the gubernatorial ticket.
I believe his abandoning his Congressional seat puts Marc Molinaro in a much better position to claim it for the GOP. His record on guns has been generally supportive, but after his ’18 gubernatorial run I would not trust him.