If you're not flying with it, get a Savior. I haven't tried one of their singles, but their double cases are wonderful. They post both inside/outside sizes so no guessing. You can order from Amazon, but here's their website so you can see what they offer. You might want to check out the Specialist LRP too. I have two regular doubles, urban warfare 51 and specialist 46 for my folder (or two Ruger No. 1's)
saviorequipment . com be sure to check the sizes for the one you want. Example, the LRP 51" is interior, the doubles those ad sizes are exterior, so check specs ext/int before sending to cart.
specialist double is my fave just cause of the outside layout but unfortunately they don't make that in 51 or 55. The classic is also nice, our youngest has some of those for his AR stuff. I didn't think I'd like them, but have to say I love em, built like a tank and I can leave all my mags, bipods, and other stuff in em so they are ready to go when I take my chassis rifles out. You're not going to tear the handles loose or ruin the zippers on these so long as you use the straps too. 20# chassis with gear, no problem.