A pork butt, shoulder, loses about 35 to 40 percent of it's weight after cooking it. If you use 4 ounces of cooked meat per sandwich which is four sandwiches per pound, you will need 6 pounds of cooked pork to get 24 sandwiches. This would be a 10-pound uncooked pork butt or shoulder. Be mindful that a lot of times people use 6 to 8 ounces per sandwich.