For extremely large LR rifles say 60 or 70#??
I had to make mine out of wood and pad the inside. Problem is, they are big and heavy.
My hunting partner has his big Longrange rifle, his Barr and Stroud rangefinder and two pairs of bigeyes in one large box (like a casket) that he made for that purpose. Everything fits in it's own place and it takes two of us to get it in and out of the truck.
I have not found any commercial cases that are wide enough to put a 6" or 8" wide stock in.
Everyone I know who has large LR rifles had to make their own.
My 30" barreled 16 1/2# rifle with a 3" wide stock will fit in a 52" hard padded gun case if I take the muzzle brake