Up until now I've used butts. 17 lbs boneless butts mixed with 5 lbs fat. The fat I get at either Publix or Winn Dixie. I get there early, tell the meat dept what I need and come back for it later. They give it to me free. Once it's in the offal bucket, they can't give it out, that's why early is best. This batch was a new thing for me, using rib trim. I had planned on grinding it Friday, but didn't get to it until Sunday----no fat on Sunday. I had 1.75 lbs vac-packed in the freezer, so that was it. 14.25 trim plus the 1.75 lbs fat. Came out good, will do it again. Thanks