Recently ordered Jpx 921 hotmetal pro irons and have been told Mizuno have run out of MCC plus 4 grips. They won't send ungripped so I can install some myself.
There is a shortage of grips not just MCC+4 , Golf Pride & Lamkin, have difficulty supplying grips, shortage of rubber, been like this for over 8 months or more
Just received a set of Super Stroke cords that I have gotten to like more to replace fairly new MMC +4s. They seem to be fully stocked, but they might not be for everyone.