You won't need too much to this project, just the following things:
1. Army Duffle Bag-I used the newer, heavy nylon style with the backpack straps and outer pocket. If you have a canvas bag lying around it will also work-the canvas one I have was my grandfather's from WWII and stank like death anyway, so I used this one I had picked up at my local flea market for about 8 bucks. You can find them on Ebay and from surplus dealers, but shop around because often surplus prices go up and down due to supply on the secondary market at any given time. If you have to pay more than ten bucks you can start thinking about a pre-made gun case-and what fun would that be? Additional fabric can come from a second bag, your local fabric store, or do like I do and keep a constant supply of old nylon bags, webbing and hardware around-you'll never know what you need.
2) Old blanket-this one was a polyester blend, but nice and soft so it won't scratch my rifle or the scope-I'm probably going to end up hanging on to this butchered blankie now, since I am going to do a second bag for another rifle.
3) Heavy duty needle and thread. I used a Dritz needle from the pack shown. My local craft store had these in a pack, and they are usually also available from Cheaper Than Dirt
in quantities of 6 or more packages. You can use a heavy sewing machine if you have one and cut this project down to less than two hours. The thread came with a hand sewing awl I got a while back-I thought I would need it for this project but it turned out the fabric was pretty easy to sew with one of the medium-sized needles in the package. Any heavier thread should do the trick, but if you want a nice match look for black or olive drab-it will show through your seams a bit.
6) Scissors-really sharp ones or EMT-style ones-the fabric is heavy where it is folded over!
7) X-acto Knife
8) Patience (I had the most difficult time finding this)
9) Zipper (optional, size may vary)