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Charl Schwartzel’s drilled-out Miura irons: A builder’s perspective



We see plenty of cavity back irons on the PGA Tour. Most of these irons have been strategically designed to position weight and center of gravity to maximize performance. Spotted this week at the AT&T Pebble Beach Pro-Am: a nonconventional set of “cavity backs” in the form of Charl Schwartzel’s drilled-out Miura MB-001 blade irons.

As first reported by’s Andrew Tursky, Charl, an equipment free-agent, bought the irons online, and after tinkering with them (obviously, Charl is a true gear nut), he felt the irons were just a bit too heavy at D6 swing weight and wanted to bring them down to around D3. These number will seem quite arbitrary to some, so to help explain swing weight, we have a short video below

Now, the question comes down to why would he drill out the irons instead of just having the clubs built to his desired spec?

In the case of Miura irons, a company founded in Japan. The iron head weights are heavier than others on the market because Japan spec irons are generally built to shorter lengths than their North American counterparts. The clubheads are noticeably heavier in the shorter irons and wedges (see chart below), which is why we see more holes in the pitching wedge vs. the longer irons.

Since the MB-001’s are a solid muscle design with no badges or weight ports in the head, there is no other way to remove the mass needed to hit a lighter swing weight for Charl—unless Miura was to produce a set heads at a lighter weights by grinding off mass during the final production steps before final finishing.

Head weight specs 3-PW starting at 245g at the 3-iron.

As a result, when built with heavier tour weight shafts (anything 110g or above) and at a standard North American length (37″ – 7 iron, or longer), the clubs will end up being heavier than what would be considered standard swing weight (usually between D1-D4). Let me please point out that in the golf club manufacturing world there are very few standard practices or measurements beyond the USGA ruler and swing weight scale. Although the phrase “standard clubs” is still common nomenclature, it applies very little to the custom club building world. 

Beyond adding mass to the grip end of the club to counteract the heavier weight of the heads, a practice known as counterbalancing, the only other option is to drill mass out of the clubhead (see full video above for further explanation). Charl reportedly did the drilling himself when fine-tuning the clubs and after a few holes got them right where he likes them.

Based on the thickness of the iron muscle and the amount of mass removed from each head (roughly six grams), these holes have no effect on the performance of the irons (but have probably killed any potential resale value on the open market—bearing in mind that last part is tongue in cheek). If Charl wins another major with these, who knows what they would be worth.

Other examples

This process of drilling out mass has also been referred to as “porting,” and club builders have been doing it for a long time. In the case of wedges, porting not only helps reduce clubhead weight, but can also help (in a very, very small way) remove mass from lower in the head to raise the CG. It’s the exact reason Callaway introduced this design feature in the original PM Grind and continues with the design philosophy today in the JAWS MD5.

With Bryson’s wedges being more than 1″ over standard length, weight had to be removed from the head.

We don’t recommend you start drilling holes in your irons and wedges just yet and suggest seeing a professional club builder to help you sort out your specs and get you dialed in. For more pictures of the clubs Charl Schwartzel is using this week, head to the GolfWRX forum: Charl Schwartzel – WITB 2020 AT&T Pebble Beach


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Ryan Barath is part of the Digital Content Creation Team for GolfWRX. He hosts the "On Spec" Podcast on the GolfWRX Radio Network which focuses on discussing everything golf, including gear, technology, fitting, and course architecture. He is a club-fitter & master club builder with more than 17 years of experience working with golfers of all skill levels, including PGA Tour players. He is the former Build Shop Manager & Social Media Coordinator for Modern Golf. He now works independently from his home shop and is a member of advisory panels to a select number of golf equipment manufacturers. You can find Ryan on Twitter and Instagram where he's always willing to chat golf, and share his passion for club building, course architecture and wedge grinding.



  1. craig adams

    Mar 12, 2020 at 12:42 am

    Charles golf game has holes in it. He’s out of the top 200? A golfer as talented as he is shouldn’t have to tinker with clubs. Manufacturers should be throwing their clubs at him. Did his game go sour since moving to PXG? Why do golfers change a winning combination? Look at Westwood and Jiminez; been playing with Pings all their career.

  2. Eldrick

    Feb 20, 2020 at 3:38 am

    Looks like his Gapr low is a glued non adjustable one.

  3. Nack Jicklaus

    Feb 12, 2020 at 1:02 am

    He should have just drilled all the way through the faces like the old “Hammer” driver. Boom!!!!!!!!!!

  4. Ima Fitter

    Feb 10, 2020 at 5:02 pm

    Love it! You don’t need to spend a ton of money on a new set of irons. As long as they are forged and you like the appearance, pre-owned irons can be fit to your swing. Change the loft & lie, change the shaft, change the grips…any qualified club builder can make them work for you.

  5. Benny

    Feb 8, 2020 at 8:02 pm

    Great catch Wrx and article. Charl left PXG a while ago. But truly suprised he couldn’t get a set directly and have them custom grinded. Anyways great details and love the comments fellas.

  6. bob stelben

    Feb 8, 2020 at 3:01 am

    Good video on swing weights. Can you explain tipping of the shaft and the reasons or advantages/disadvantages?

  7. Steve

    Feb 7, 2020 at 3:23 pm

    I thought Schwartzel was a PXG guy? Guess I am mixing up who Parson’s friends are. And I agree….drilling holes in Miura irons is like adding your own touch up paint to the Mona Lisa. To each his own, I guess.

    • Funkaholic

      Feb 7, 2020 at 4:55 pm

      I doubt a pro is bagging those Miuras for status, he is going to play the grooves off of those babies, appearance is for weekend hackers.

  8. Donn Rutkoff

    Feb 6, 2020 at 3:17 pm

    Palmer probably drilled out hundreds of clubs. Tinkering was common. To suit your own swing.

  9. Fergie

    Feb 6, 2020 at 12:33 pm

    Drilling Miuras like that is, well, blasphemy. He should just get it over with and get CB’s.

    • Funkaholic

      Feb 7, 2020 at 4:53 pm

      CB’s are not the same idea at all, he is reducing swing weight, a CB redistributes weigh to lower in the head making raising MOI and them easier to launch.

  10. Mike Cleland

    Feb 6, 2020 at 10:32 am

    I grew up playing D5 S/W clubs with standard lengths. Does any manufacturers make heavy headed clubs or do they just shove weight down the shaft & change the center of gravity. All my clubs are covered with lead tape. Any suggestions?
    PS: I really enjoy your blogs

  11. jgpl001

    Feb 6, 2020 at 3:50 am

    Nasty workmanship on a quality blade

    He appears to be missing the drilled effect of hs old pig’s……

  12. Dennis

    Feb 6, 2020 at 1:28 am

    Do all the pros go for swingweight instead of MOI-Matching?

  13. Gurn

    Feb 6, 2020 at 12:19 am

    Those Miuras need that treatment like a hole in the head

  14. bill bourne

    Feb 5, 2020 at 8:01 pm

    Does drilling out the backs affect the overall thickness spec?

    • JP

      Feb 6, 2020 at 8:32 am

      Huh? Overall thickness spec? What is that?

      • Tim Armington

        Feb 7, 2020 at 7:54 am

        You dont know what a thickness spec is??? Wow.

        • Funkaholic

          Feb 7, 2020 at 4:56 pm

          Ha! This guy doesn’t know what thickness spec is!

          • maroon

            Feb 8, 2020 at 4:32 am

            I know but it has nothing to do with golf 😉

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Whats in the Bag

Anirban Lahiri WITB 2020



  • WITB accurate as of January 2020

Driver (two models): Titleist TS3 (9.5 degrees, D4 SureFit setting)
Shaft: Aldila Rogue Silver 130 M.S.I. 60 TX


3-wood: Callaway Epic Flash (15 degrees, DS OptiFit setting)
Shaft: Mitsubishi Tensei CK Pro Blue 70 TX


5-wood: Ping G410 (17.5 degrees)
Shaft: Mitsubishi Tensei CK Pro Blue 80 TX


Hybrid: PXG 0317 X (22 degrees)
Shaft: Mitsubishi MMT UT 105 TX


Irons: Srixon Z 785 (4), Srixon Z 945 (5-PW)
Shafts: Nippon N.S. Pro Modus3 Tour 120 X

Wedges: Titleist Vokey Design SM7  (50-12M)
*We were unable to photograph Lahiri’s other wedges

Putter: Toulon Design Austin Stroke Lab

Putter: OnOff Prototype


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A Deep Dive: The equipment timeline of David Duval, 1993-2001



Like Tiger, David Toms, and Fred Couples there are certain players that I have been obsessed with for years. If you go to my Instagram, you can see it in plain sight. When it comes to DD it was more than the what, it was the why, the how that sparked my curiosity. Let’s face it, in 2000 with the Mossimo gear, Oakley shades, jacked-up physique, and on Titleist staff, was there ever a cooler looking player?

No. There wasn’t or isn’t.

That’s where my interest in Larry Bobka came about. I saw David and Larry walking the fairways of Sahalee at the ’98 PGA Championship.

At the time, I was already knee-deep in David Duval fandom but that experience took me over the top. Bobka had a handful of clubs in his hands and would pass DD a 970 3-wood, Duval would give it a rip and the two would discuss while walking down the fairway. Of all my time watching live golf, I have never been so awestruck.

This is an homage to David’s equipment during his prime/healthy years on the PGA Tour. From his early days with Mizuno, into the Titleist days, and finally Nike.

1993-1995 Mizuno

*This was an interesting time for Duval from an equipment standpoint. The pattern of mixing sets to put together his bag began and it was the time he transitioned from persimmon (Wood Bros driver) into metal woods. It was also the beginning of his long relationship with Scotty Cameron, a relationship that still stands today.

What was in the bag

Driver: TaylorMade Tour Burner 8.5 w/ Dynamic Gold X100 (*he also played with the Bubble XHKP Prototype)


King Cobra @14 w/ Dynamic Gold X100

TaylorMade Tour Issue Spoon @13  w/ Dynamic Gold X100


1993: (1) Ping Eye2, (3-PW) Mizuno Pro TN-87 with Dynamic Gold X100

1994: (1) Ping Eye2, (3-PW) Mizuno Pro TN-87 with Dynamic Gold X100

1995: (2,3) Mizuno TC-29, (4-PW) Mizuno TN-87 with Dynamic Gold X100

Wedges: Mizuno Pro (53, 58) with Dynamic Gold X100

Putter: Scotty Cameron Classic Newport (35 inches, 71 lie, 4 degrees of loft)

Ball: Titleist Tour Balata 100

Glove: Mizuno Pro

1996-2000 Titleist

The beginning of the Titleist years started off quietly. There wasn’t any new product launched and David wasn’t quite the star he would become 12-18 months later. However, it gave Titleist the opportunity to get to know DD and his overall preferences, which aren’t dramatic but certainly unique. He didn’t win in 1996 but did qualify for the Presidents Cup Team and finished that event off at 4-0. So the buzz was going in the right direction and his peers certainly took notice.

It was 1997 that things took off on all fronts and it was the year that Titleist made David Duval the face of the DCI brand and with that decision spawned the greatest cast players cavity ever: the 962B—and also equipped David Duval to go on a 3-year run that was surpassed by only Tiger Woods.

Hence the deep dive article I wrote up earlier this month

What was in the bag



TaylorMade Bubble Tour 8.5 w/ Bubble XHKP Prototype


TaylorMade Bubble Tour 8.5 w/ Bubble XHKP Prototype

King Cobra Deep Face 9 w/ Dynamic Gold X100

Callaway Warbird Great Big Bertha 6.5 w/ Dynamic Gold X100, True Temper EI70 Tour X

Titleist 975D 6.5 (no line heavier head weight) w/ Fujikura Prototype X


Callaway Warbird Great Big Bertha 6.5 w/ True Temper EI70 Tour X

Titleist 975D 6.5 (no line heavier head weight) w/ True Temper EI70 Tour X

1999: Titleist 975D 6.5 (no line heavier head weight) @ 7.5 w/ True Temper EI70 Tour X

2000: Titleist 975D 7.5 (no line heavier head weight) w/ True Temper EI70 Tour X



King Cobra @14 w/ True Temper Dynamic Gold X100


King Cobra @14 w/ True Temper Dynamic Gold X100


Callaway S2H2 (1 Dot) @14 w/ Fujikura Vista Pro 90X

Callaway Steelhead 3+ @13 w/ RCH 90 Pro Series Strong

Titleist 970 (Dark Grey Head) @13 w/ True Temper EI70 Tour X (only tested this one)


Callaway S2H2 (1 Dot) @14 w/ Fujikura Vista Pro 90X

Cobra Gravity Back 14.5T w/ True Temper EI70 Tour X



(2-PW) Titleist DD Blank Prototype w/ True Temper Dynamic Gold X100 (w/sensicore)

(2-PW) Titleist DCI Black “B” w/ True Temper Dynamic Gold X100 (w/sensicore)

*This prototype set was a blank set of the DCI Black “B” but with sole modifications. 

1997, 1998, 1999, 2000: (2,3) Titleist DCI Black (4-PW) Titleist DCI 962B w/ True Temper Dynamic Gold X100 (with sensicore)

*David liked the original prototype version of DG Sensicore X100 that had weight removed from the center of shaft to create better feel and a slightly higher trajectory

24 Feb 2000: David Duval watches the ball after hitting it during the World Match-Play Championships at the La Costa Resort & Spa in Carlsbad, California. Mandatory Credit: Harry How /Allsport


1996: (52 @53, 58) Mizuno Pro, (56 @57) Cleveland 588 RTG w/ True Temper Dynamic Gold S400

1997: (53) Cobra “Trusty Rusty”, (57 @58) Cleveland 588 RTG, (58) Titleist Bobka Grind, (57 @58) Cobra Trusty Rusty w/ True Temper Dynamic Gold S400

1998: (53) Cobra “Trusty Rusty”, (57 @58) Cleveland 588 RTGw/ True Temper Dynamic Gold S400

1999: (53) Cobra “Trusty Rusty”, (57 @58) Cleveland 588 RTG w/ True Temper Dynamic Gold S400

2000: (53) Cobra “Trusty Rusty”, (57 @58) Cleveland 588 “Gun Metal” w/ True Temper Dynamic Gold S400


1996: Scotty Cameron Classic Newport 1 35 Inches, 71 Lie, 4 Degrees of Loft, Scotty Cameron Long Slant Neck Laguna Custom (double welded neck)

1997: Odyssey Dual Force Rossie 2, Scotty Cameron Pro Platinum Newport “Beached”  35 Inches, 71 Lie, 4 Degrees of Loft w/ PingMan “Blacked Out” Grip

1998, 1999, 2000: Scotty Cameron Pro Platinum Newport “Beached”  35 Inches, 71 Lie, 4 Degrees of Loft w/ PingMan “Blacked Out” Grip

2001: Nike Golf and The Open Championship

The relationship with Titleist Golf ended quickly and when David showed up to Kapalua with a non-Titleist stand bag the rumor mill went nuts. The story (although super speculative) was that David opted out in the middle of a $4.5 million per year deal with Acushnet, a lawsuit followed, but Davids’s stance was that he had a marquee player clause that allowed him to walk if he wasn’t “marquee” aka highest-paid.

Apparently he had a point, Acushnet had recently inked big deals with Davis Love and Phil Mickelson leading someone on the outside to do the math. However, I’m not an attorney, wasn’t there, and have no clue what the legality of any of it was. Point is, he walked and landed at Nike with a new head-to-toe contract. 



Titleist 975D 7.5 (no line heavier head weight) w/ True Temper EI70 Tour X

Titleist 975E Prototype 8.5 w/ True Temper EI70 Tour X

Nike Titanium w/ True Temper EI-70 II Tour X (pictured below)

Nike Titanium Prototype 7.5 w/ True Temper EI70 Tour X (featured image)


Callaway Steelhead Plus 4+ @15 w/ RCH 90 Pro Series Strong

Nike Prototype @14 degrees w/ True Temper EI-70 Tour X

Sonartec/Excedo (SS-03 head) Driving Cavity @14 w/ Fujikura Vista Pro 90X


(2-PW) Titleist 990B w/ True Temper Dynamic Gold X100  (with sensicore)

(2-PW) Nike Prototype “DD” Grind MB w/ True Temper Dynamic Gold X100 (with sensicore)

(2) Titleist DCI Black w/ True Temper Dynamic Gold X100  (with sensicore)



(53) Cobra “Trusty Rusty”, (57 @58) Cleveland 588 “Gun Metal” w/ True Temper Dynamic Gold S400

(53,58) Nike DD Grind w/ True Temper Dynamic Gold S400

PUTTER: Scotty Cameron Pro Platinum Newport “Beached”  35 Inches, 71 Lie, 4 Degrees of Loft w/ PingMan “Blacked Out” Grip


Over the years the one constant was David’s iron and wedge specs. As a shut-faced player he has always favored traditional lofts in his irons. However, a cool thing to note is his lie angles remained constant 59.5 (2-4), 60 (5-9). The running theory here was being a shallow (low hands) and shut faced player, keeping the lie angles at a constant (flatter) lie angle allowed him to feel like his angle of attack could remain the same for each iron. It’s just a feeling but that’s what he did. If the “why of it” is true, it looks like he was doing Bryson things before Bryson did.

David Duval Iron/Wedge Specs


  • 2-17/59.5/40.25/D5
  • 3-20.5/59.5/39 1/6/D4
  • 4-24/59.5/38 9/16/D4
  • 5-27/60/38 1/16/D4
  • 6-30.5/60/ 37 9/16/D4
  • 7-35/60/37 1/16/D4
  • 8-39/60/36 9/16/D4
  • 9-43/60/36 5/16/D4
  • P-47/61/36/ 1/16/D5
  • GW-53/62/35 5/8/D4
  • LW-58/62/35 9/16/D6

Whew…since this prolific run, David transitioned into some interesting projects with smaller companies like Scratch, B.I.G Golf (AKA Bio-engineered in Germany), back to the mainstream with Nike, and most currently Cobra Golf.

I hope you all enjoyed this walk down memory lane with me, Duval is not only fascinating from a career standpoint but digging into the equipment of DD has been quite the experience.

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“Why can’t I hit my new irons to a consistent distance?” – GolfWRXers have their say



In our forums, our members have been discussing irons and how to hit your numbers consistently. WRXer ‘Hubb1e’, who is a 15 handicap, is having issues and says:

“I recently upgraded from 20 year old Taylor Made 360 irons to a set of custom-built Callaway Apex 19 Forged irons. Old irons were traditional cavity back. New irons are categorized as players distance irons. Both have the same fit.

My new 3 iron will go 230 yards or 130 yards and not even make it far enough to reach the fairway. My new 7 iron will typically go 160 yards but will often will fly 175 yards or drop out of the air at 120 yards. I can’t control the distances of my new irons, and I spent a fortune custom fitting them to my swing. Why is this happening? This was never an issue with my old irons. A bad hit would go 10-20% shorter, but I never had balls fly over the green or completely fall out of the air. What is going on with my new equipment?”

Our members offer up their solutions in our forum.

Here are a few posts from the thread, but make sure to check out the entire discussion and have your say at the link below.

  • ThreeBoxers: “Strike quality is your answer. Tech or no tech, irons will not have 50-yard distance discrepancies. Not super familiar with the Apex irons, but they’re pretty forgiving no? You might lose 10 yards on toe or heel strikes but 40, 50? You’re probably hitting it heavy. If they have a beveled edge, it may mask the feeling of hitting it fat a bit, but not the result. My Mizunos have a pretty aggressive front edge grind which helps a ton on heavy shots. It’s the difference between landing 15 yards short and 50 yards short. +1 on using foot spray to check impact.”
  • extrastiff: “It also would not hurt to check your swing speed. Even strike being terrible that’s a large discrepancy. Maybe your last build had a weight that helped you get consistent swing speed.”
  • WristySwing: “I would say inconsistent strike is the biggest issue. Now that can mean a couple of things. It could mean you, as in the person swinging, are not hitting the ball properly because of inconsistent delivery. The other option is the fit is bad, and it is causing you to be extremely inconsistent because you cannot feel the head. It might be a little bit of column A and column B. However, I would lean more towards column A in this scenario because even a horrifically misfit set someone could get used to it eventually and not have 100 yards of discrepancy in carry shot to shot. I’ve seen people who are playing 50g ladies flex irons with fat wide soles who are very shallow and swing a 6i 92mph still not have 100 yards of carry flux with their sets. If your miss is toe-side 9/10x that is because you are coming too far from the inside. When you get too stuck on the inside you typically stall and throw your arms at it. When you break your wrists (flip)/throw your arms at it you get a very inconsistent low point average that often manifests in extremely fat or thin strikes….typically fat since your squat and rotate is out of sync with your release. As others have said, get some impact tape/foot powder spray and see where you are actually making contact. Then if you can get on a video lesson and see what the issue is. As of right now, we can all only assume what is going on. If your low point control is good, you don’t get stuck, and you are hitting it in the middle of the head — then fit comes into question.”
  • larryd3: “I”d be on the phone to my fitter and setting up a time to go back in and see what’s going on with the irons. You shouldn’t be getting those types of results with a properly fit set of irons. When I got my fitting earlier this year at TrueSpec, the fitter, after watching me hit a bunch with my current irons, focused on increasing the spin on my irons, not on distance but on consistency. So far, they seem to be working well when I put a decent swing on them.”
  • fastnhappy: “One possibility that wouldn’t necessarily show up indoors is sole design and turf interaction. You may have a real problem with the newer clubs because of a sole design that doesn’t work for your swing. That’s hard to tell when hitting inside off a mat. If so, you’d see major distance inconsistency because of strike. The feedback I’ve seen on the players distance irons is exactly what you’re describing… difficult to control distance.”

Entire Thread: “Why can’t I hit my new irons to a consistent distance?”

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