Cutting at that muzzle can be a very consistent way to get a patch to be centered rightly thus unto the gun's bore.
Recovered patches cut at the muzzle show great concentricity. It can be a might bothersome though in the field without the aid of some type of rest to lay the piece against when cutting. Pre-cut patches are more convenient for hunting. It can be quite a trick to get at the muzzle in such conditions as having no rest for the rifle or support as in the hunting environment. Be careful not to nick oneself!
Still, one can go to Jo-Anns and find the proper fabric of which there are several. Take along a micrometer and measure the thickness. Buy what you need, or perhaps several different types. Look for a strong natural fabric with a tight weave, such as pillow ticking or denims. Avoid synthetics such as polyester, they are no good for our purposes and can melt in the barrel.
Then, one can lubricate them with all manners of natural lubricants, there are endless recipes and combinations. Trying them along with varying the quantity and type of powder, among other factors, all play in getting the piece to "shoot sweet" as it were.
One can cut at the muzzle, or use what is referred to as a "hollow punch" which takes such form as an inverted cone with a handle atop it. It produces a circular patch. Some hollow punches are of superior quality, though all may need to have their edges dressed to keep them cutting patches rightly.