Do-All Flight Proof Case
is a monster of a case but worth every penny in my book. There is only a handful of cases that guns over 52" will fit and I wouldn't fly with half of those. The only problem with this case is the fact there is only two latches. When you put a 14 lb rifle in there and lift it with the handle between the latches there seems to be some flexing. There is a large v groove there and it would never come apart, it just feels funny.
Seems to be an industry standard at 52". If your rifle is over 52" this would be your best option for a hard case.