I use "This gun case from Cabelas".
and my hunting buddy has one also. They easily handle 30" barrels plus muzzle brake, with room to spare, and it doesn't break the bank when you buy one. Both guns have target/tactical type turrets also.
All of the paper work that comes with it is from Impact Case and Container, as in Shawn's suggestion. For the price it's well made. You can spend less, and you can spend more, it's just up to you. Just don't put a $$$$$$ gun in a $29.00 case and expect it to remain intact.