Endgame Thanos question.

Something I don't know was clear about Thanos without the gauntlet and later stones, if by some opportunity in some timeline... Let's say FRANK CASTLE (because it removes hesitation and uncertainty in general) put a.45 in the eye of Thanos and just kept point and clicking, would that had gotten the big fella down?

I know in and out of universe why that isn't any fun and how it "could never happen" etc... but just a question about raw resilience and the such I guess.