What’s better than a forged muscleback iron at address? Nothing, except maybe an iron that looks the same, plays the same and has more forgiveness.

Callaway has attempted to create such an iron for 2013 with its X Forged, a tour-inspired forged cavity back designed by Roger Cleveland that offers cleaner looks and better performance than its predecessor, the Callaway RAZR X Forged.

Luke Williams, senior director of global woods and irons for Callaway, said the most popular irons on the PGA Tour and European Tour right now for the company are not its forged cavity backs. It’s the company’s muscleback offerings — last year’s RAZR X Muscleback irons and their predecessor, the Tour Authentic X-Prototype irons that Callaway tour players are trusting in their bags.

The reason is not necessarily that tour players don’t need the added size and forgiveness of a forged cavity back, either. Yes, one of the reasons musclebacks are more popular with tour players than forged cavity back irons is because of their clean looks. But there are also performance reasons.

According to Williams, Callaway’s recent musclebacks have been a hit because of what the company is calling CG Height progression. CG (Center of Gravity) Height Progression puts the center of gravity lower in the long irons for the higher trajectory that tour pros want. It also places the CG higher in the short irons for a flatter trajectory. Callaway’s previous forged cavity back irons, the RAZR X Forged, had the opposite CG progression. The center of gravity was actually the lowest in the short irons.

Callaway also got feedback from tour pros that the RAZR X Forged irons had a tendency to dig through impact, while the muscleback irons went more smoothly through the turf. So the new X Forged were designed to have what Williams called “a slightly wider muscleback sole.”

Aesthetically, the 2013 X Forged look more like Callaway’s musclebacks as well. They have a shorter blade length than the RAZR X Forged, but it’s not quite as short as the musclebacks. The 2013 X Forged irons also lose the high heel and sharp toe that gave the RAZR X Forged a polarizing appearance, opting for a face profile closer to the musclebacks.

“Pretty much every player that puts the muscle back iron down like the way it looks,” Williams said.

They X Forged irons go farther than the RAZR X irons as well. They do so, according to Williams, for two reasons:

1. The clubs have one degree stronger lofts (21-degree 3 iron, 46-degree pitching wedge)
2. CG height progression

Despite what many believe about modern iron design, the lofts were not strengthened simply to make the ball go farther. Stronger lofts are a result of tour feedback. Williams said that Callaway sets the lofts on its tour irons based on tour trends. And it’s vital for Callaway to follow the loft trends on tour, since changing the loft of an iron also reduces the bounce on an iron, which can lead to digging. Bending an iron one-degree strong won’t change a iron’s response to the turf that much, but bending a club stronger than that can certainly change things.

“We really design a forged iron product like the X Forged for the tour,” Williams said. “But we know if we get them right, they will work for amateurs as well.”

CG Height progression makes the X Forged long irons go farther because since they’re launching higher, they’re also carrying farther. It also makes the short irons go farther thanks to a more piercing trajectory.

Golfers looking for a tour-quality ball flight will also be happy to learn that the new X Forged irons come stock with a Project X PXi shaft, a lighter weight model of the popular Project X shaft with similar flight characteristics.

“We felt that PXi was the best fit, given the trend of going lighter with iron shafts,” Williams said. “Players are recognizing the value of lighter shafts if [those shafts] can maintain the consistency.”

Williams expects that the X Forged will become Callaway’s most popular iron on tour, knocking some muscleback irons out of the bags of Callaway staff players. Callaway has already received a glowing endorsement from Phil Mickelson, who was not very interested in switching from his musclebacks. He showed up to a recent Callaway ad shoot with a full set of X Forged irons in his bag and said he might put them in the bag in China at the HSBC World Golf Championships.

The 2013 Callaway X Forged irons will retail for $999.99 per set and will be available on Jan. 25, 2013.

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