if you really want to be sneaky use what I use. Go to your nearest music store and buy a cheap soft case for a electric base. Neighbors think I am going to band practice and not the rifle range.
A .50 cal barrel cover fits the A4. A section could be added to extend it to make up the length for the A6. It lacks a handle but that is an easy mod.
I added some ties to it and it covers the BMG while mounted on my jeep.
I bougth this one for seven dollar surplus.
Case reads cover cal. 50 barrel 6591031 met oct 1991