Diving Unlimited International updated their Sniper Weapons Waterproof Bag by incorporating shoulder straps, a drag loop at the top and inner straps to keep the weapon from moving around inside the bag.
Additionally, they’ve introduced the new plastic waterproof zipper. However, like its predecessor, it still features an oral inflation tube.
www.dui-online.com/products/waterproof-weapons-dry-bags
This is worth looking into for civilians too, anyone who trains in all weather or hikes with a rifle