Yes.... denim is tough. It is also thick and in my experience requires use of a small ball. More easier to go with something thinner, like pilllow ticking which is what I use.Denim is tough to beat as a patch material. I started with pillow ticking and later found mattress ticking which was thicker and a bit tighter weave. Then on to duck and finally to denim and heavy, unbleached canvas. Pillow ticking does work great in many rifles and I use it in my .54, still.
BTW, I wash my new ticking only once without any detergent then dry in dryer. Works for me.