Ill be running #3 and #6 shot mixed.
I'm curious as to why you're using a "duplex" load of shot?
The SxS was one of the most popular shotgun styles for more than one and a half centuries for a good reason.
(I own four btw, one caplock 20 gauge and the rest are modern)
If #6 is heavy enough for what you're hunting, then ¾ of an ounce will give you a better pattern, farther.
IF the #6 isn't going to get the job done, then I'd say ¾ ounce of #3 will up your odds for a clean harvest rather than a 50/50 mix of #3 and #6 which halves your #3 sized shot quantity....
I'd say load one barrel with the #3 and the other with #6. THAT's the whole advantage of a SxS.
Often the procedure is to load the barrel which works off the forward trigger with the smaller shot, as that's the trigger that's quickly acquired when you flush game close. Sometimes really close, and if you hit that bird with a ¾ ounce load,from a duplex load, your reward may be a pile of bloody feathers.
If an unwary squirrel is about and you somehow get right on top of it, or a bunny freezes too long and you get very close...if either happens and you go for the quick shot when either flushes...., well at that distance a load of #6 alone will do fine.
The barrel that fires from the aft trigger if you load it with #3 and you see a squirrel or rabbit at a distance, you should have the time to move your finger to the aft trigger..., or to try to creep a bit closer and then select the aft trigger (but even so you're not going to be nearly as close as you'd be when flushing a bird, eh?). So at the farther distance, you're delivering less pellets on the game.... BUT...the #3 is just a tad less than 50% heavier than the #6, so require less hits to harvest that squirrel which was foraging, or that rabbit that thought you couldn't see him at a distance and as you crept closer and the rabbit thought to pretend to be a fuzzy rock.
LD
