Never hunted with one but have seen them work cows. They are very intelligent animals & I am certain can do the work required. Acclimating to gunfire needs to be a gradual process that links the gunfire to something the dog likes. I start with cap pistols at feeding time working up over a month or so to gunfire with retrieves. Putting a dog in a situation where there are multiple guns shooting at a flock as a first gunfire experience will probably cause a gushy dog.

My bigger issue is how a border collie handles being cold & wet. They simply were never intended to retrieve ducks in freezing water. My BIL nearly killed a Boykin Spaniel hunting in the Arkansas timber one year. Made me very careful with my dogs. At a minimum, buy a neoprene vest & be prepared to quit at the first sign the dog is cold.

I agree that dogs need jobs but am afraid you will be pounding a square peg in a round hole.