I am in same boat.
Wanting to try some 2 3/4" Longbeards and wanting #6 but what I am finding is they are offered in #5 so thinking of some Rooster XR #6 but really don't need those since I have several boxes of #4, #5 & #6 Magnum loads.
Not sure why they would only offer the Longbeard in #5. At only 1 1/4 oz. you think they would offer a #6 load. Also be nice if they were a 1 3/8 oz load.