RWTF, I think Browning had a different definition of "lightweight" for those A-5's. (The same really goes for the old Sweet 16's as well.) Yes, both lighter than the "standardweight" guns . . . but a bit like comparing a linebacker to an offensive tackle: neither one very light by "normal" standards.
But I can still pick up a Sweet 16 and shoot it about as well as anything. I think it's true with those old humpbacks: You can either shoot them or you can't. I had no idea that I could until a fellow shooter told me of a friend of his who had both a Standardweight 16 and a Browning 1903 .32 for sale. Shot both well. Wish that .32 had had a bit more punch.