Just for curiosity, I checked four British gun authors - Gough Thomas, Burrard, Churchill and Tucker. Couldn't find anything said about how to close a SxS - suggesting that perhaps the question isn't worth comment, and the shooter is free to use whatever method he prefers, so long as it doesn't endanger anyone or obviously abuse the mechanism. The Brits who made them referred to most SxSs as 'snap' actions, referring to the act of closing them...could that be a hint?

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