back in the day i used a 5.11 vtac 42" double rifle soft case, then pack that into a pelican 1750...... you got a hard lockable case for storage, and a nice soft case to carry the guns from the hotel to match venue. (lock the hardcase, handcuff to bed frame for storage)
when i upgraded to a versamax (from a 590a1 18.5"bbl) i had to get a bag 48" long to fit the versamax, i bought the US PEACEKEEPER 48" 3gun case and it fit everything perfectly and still fits inside the pelican case