I cock one barrel at a time on the bird getting up. I am slower than my friends with their Superposed guns, but seem to get my share of birds. I shoot better with hammer guns on upland birds than my AyA number 2 in 20 gauge.
I have been shooting a Bernardelli Brescia 12 gauge since 1965. There have been quite a few other hammer guns, but the Bernardelli is a keeper, showing lots of loving wear to the finish.