Dear CptCurl,
I don't mean for this to sound like a brag, but rather to establish my history. I have been a Cowboy Action Shooter for 15 yrs. I have won 4 world championships plus the Master Gunfighter event. These are 4 gun events...2 SA revolvers, lever action rifle, double bbl. shotgun. SPEED and accuracy are paramount. Thus said...focus on your target/quarry...cock BOTH hammers by bringing the thumb and what ever if left of or needed of the hand, FULLY across BOTH hammers...
make sure (by way of practice) both hammers are FULLY cocked...point/aim at the intended "target"...let fly with each bbl. in sequence. (usually, "float" the target on the front sight.) As a matter of a hint...make sure the checkering is so sharp on the hammer spurs, that if you don't get it cocked, you have at least left a portion of skin in the checkering. (you won't make the same mistake the next time) SP2