Did you mean quilts? It would be a huge help if you would post a picture of the item you are referring to. There are many styles and types of gun cabinets. They range from simple glass cases to huge wooden racks.
A gun case can make a wonderful quilt display case. If the door is glass, leave it on! This will keep lots of dust off the quilts. Clean the gun case with tsp or vinegar and water. Remove every drawer, shelf, hook, and rack. There may even be traces of gunpowder, depending on how it was used previously, so cleaning every corner is important.
If there are drawers large enough to store quilts, add a drawer liner and fill the drawers. If you happen to have drawers stacked one above the other, you can remove the bottom from one or more of the upper drawers. This might make one large drawer out of 2-3 drawers. If you have quilting supplies, maybe you can store those in a drawer.
If your case is basically a vertical open box, use any racks you removed and cleaned to install racks for as many quilts as you have room for. One quilt can be displayed in front of another, and you can rotate them (which will also keep them from getting sun-faded.) If you have wood hooks or pegs, you should be able to store one regular or two baby quilts inside the case, on the side walls.
Don't forget the top of the case and the outer sides for display, also. You could just display one quilt at a time, but museums and restored antique homes often display as many quilts as possible. It’s your choice.
My choice would be to redo the entire case in antique white with doily stencils. Best wishes, and please post your project on Hometalk! Jewell
I think this one is darling, it has that farmhouse flair and you can see the pretty quilts through the wire. If you like, you could always add glass behind the wire for protection. https://www.hometalk.com/8312115/old-gun-cabinet-transformed