I have been making this jerky for 15 years +. Made it for the Carriers at the local Post Office. I Settled on 15-20 percent fat Ground Beef. No fat beef is tastless. I would buy  in 5 pound increments then have the butcher break it up into 1 pound pieces. 1 baggie spice and perservative each per lb of ground beef. Some liked it hot so I added a tblsn+ or - red pepper flakes per pound. Make 5 pounds or more each time. Do not run this through a mixer. Comes out hard and rubber like. Hand Mix then place in jerky gun. I use a Large gun with twin head cutting down on time. Cook anywhere from 8 to 10 hours depending on the outside temp. I use Excalibur 9 tray unit set too 160 degrees. Let it cool and bag it up then refrigerate. This comes out so tasty and tender even your toothless relatives can chew/eat this witout any problem. I am one of those toothless wonders. Chew this no problem. Good luck my friends.