I’m thinking about soft stepping the shafts in an older set of irons that I have.  They are regular flex, and I would like to have them play closer to a senior flex.   I was thinking about taking the shaft from the 4 iron and 5 irons (which I no longer use) and putting them into the 6 and 7 irons, and so on down the set.  While this would undoubtedly make each club play 2 shafts softer, would that be enough to achieve a senior flex?  I don’t have a frequency machine, so I have no way of measuring this……