potbunker What benefit do you realize back weighting the irons?
I do this as well. Probably mostly for static/total weight. The 100g iron shaft profiles fit me, but even with MOI matching the irons feel light to me. The last few sets I would put a 5g backweight in the 8i, a bit heavier in the 7i and so forth. My fitter actually built the original set with 5-P having the same MOI and same total weight. Since then the irons get a bit lighter as they get longer.
I really struggle with tempo and takeaway when the club is really light. Also maybe it's in my head, but I swear I hit a lot more fat shots without the backweight. Years ago I kept chunking my 5 and 6 irons and after reading up on backweights I put lag bolts in the butt of the grips......almost no fat shots. I was sold.
