The Mizuno JPX-850 Forged iron is a pretty club with more distance than most other players irons. The feel is harder than expected for a Mizuno with forged" in the name.
Boron. That's the big selling point behind the new Mizuno JPX-850 Forged irons. Mizuno claims that they've been working for 6 years to add boron to their Grain Flow Forging process, and the result is an iron that produces more distance than traditional forged irons.
Whether it's the boron, the "Ultra CNC Milled Pocket," or something else, the JPX-850 Forged irons are long. In fact, in our testing, they were longer than their SGI brother, the JPX-850. We found that these produced more ball speed and had lower launch and spin. All that added up to 9 more yards total (7 carry), on average.
In terms of the forgiveness, the JPX-850 Forged is average for this category. Slight mishits will still end up somewhere on the green, but you'll be in bunkers and lakes if you wander too far from the sweet spot. Mizuno recommends these clubs for 6 to 16 handicaps, and I think that's right on the mark. They definitely don't stand out for forgiveness, but they're certainly easier to hit than blades.