Here are some of my thoughts, Weber. If I wanted to add 4 swingweight points to my clubs I’d consider one of the following: 1) adding weight and a cork down the shaft, 2) adding a half inch extra length to each club (1/2” = 3sw pts.), 3) pulling the shafts and redoing the swingweight with tip weights, 4) using lead tape on the back of the heads. Of these options I’d be most inclined toward the lead tape because it gives the best performance even though it messes up the appearance of the clubs. It’s also a great first step to be sure the new swingweight is right because you can easily undo it. Since you’re using a lighter graphite shaft, adding a 1/2 inch may also be an option. Most clubmakers build graphite shafted irons a half inch longer than steel because of the lighter weight (38-38.5” 5 iron). I wouldn’t consider hot melting. Simplest way other than lead tape may be #1. I’m sure you’re familiar with all these options, but I’m chiming in! Hope these thoughts help! Cheers! Michael