I use Stanley 28" Fat Max tool boxes to carry my 2A6 Leopard, M-26 & M41 around.
The Leopard fits just fine with the gun turned backward.
Forward, not so much.

First timeI tried to put the Leopard in the box it would not fit, I did not feel so good.
I thought of was to modify the box for a few days then suddenly turning the gun to the back popped into my head ( Eureka!! ), and did I ever feel stupid.

Wayne