Mostly due to shaft lengths. Old standard 5 iron used to be 37.5, then 37.75, now (at least for us) we are at 38″. If you look at some of the OEM’s, they are all 38″ – 38.5″ depending on the model. Players irons tend to be 38 and GI irons tend to be 38.25 to 38.5. When they are longer than the 38, the head weights have to be a few grams lighter if you want to try to maintain traditional ranges for swing weight. You can always add weight, but you can’t take it away, so the slightly lighter head weights than the old standards are most likely to be the new standard. We are between 252 and 254 on a % iron on all our models. 254g for a #5 iron has been the standard for many years and that is what I did on the TS4. The TS1IM is 253 and the TS3 is 252. All are completely within a range that should complement a wide range of builds with a wide range of component weights, that should keep swing weights within normal ranges. Of course, the overall component weights and the length is what ultimately determines what the swing weight will be. As I have said many times, I really do not care what a swing weight number is, just that it is consistent within the set and that what ever it is the player can feel the head through out the swing. C0, C5, D0, D5 really doesn’t matter as long as the player likes the feel and has good performance.
Britt Lindsey
It’s all about swing speed and hitting it farther.