I have recently found with age that MOI balanced clubs with progressive swingweight work well for me. Providing the lighter weight in long irons and heavier feel in short irons. While I can get them close before assembly I always seem to need to make adjustments to two or three of the irons by adding one to five grams of weight. While lead tape works it is a shame to spoil the look of such an outstanding looking muscleback appearance. I also can use shaft tip weights but any revision means either tearing the club apart or pouring powder weight down shaft. Neither of which is appealing.

What I am wondering is if I could inject a glue/powdered tungsten mix in thru the sealed hole in the end of the head itself. Since it is hollow and I can get the weight on the bottom back surface. It would be accurate and very easy to get extremely precise match between clubs.

Has anyone done this or is there a reason not too? Also what is used to plug the hole in the end. I am sure I could find something similar?