Struggling with irons

Question
I use mizuno mp3 irons and when I play I lack distance with each club, however on the range I hit them a distance I am comfortable with.
Not sure if this is linked but my 4wood also goes about the same distance as my driver, I hit both fairly strait and consistent but driver sticks to 230-240, same as 4 wood off the deck.
My irons are oversized half an inch, i bought them 2nd hand, and I'm 5ft10, so maybe that's the problem?
I'm shooting around 80 consistently the days and feel if I can add more distance to my irons I'll consistently be in the 70s.
Any thoughts?
Thanks!

Answer
Hi there and thank you for asking.

1. Any consistent differences between the range and the course are all attributed to mental inconsistencies.  This has to do with how you approach the shot, pre-shot routine, and mindset during the swing, including specific goals.  This is all provided that there is not something actually different in your range, like down slopes or always down wind etc....

2. It is not unheard of for a player to hit a driver the same or worse distance than their 3 wood, so a 4 wood, although a stretch, is still possible.  This can be due to hundreds of reasons.  Some common ones are club lofts, club head composition, shaft, the way you tee, your spin rates, your angles of attack, the total weight of each club, etc., etc., etc....  Would only be able to narrow it down with your trial and error, changing one thing at time on your own, or having a pro look at you there, hitting both shots.

3. Equipment type is an issue with some players, depending on how much it does or not fit you and your type of swing/body.  An oversized clubhead only largens the sweet spot but harder to be real accurate... it should not be an issue for most players above scratch.  If you mean an inch LONGER in the shaft, then yes, that is not good, it will ruin your lie angle and your ball will tend to pull or draw left even when you dont want to, causing to to "hold" on to fix something that is not even your swing's fault.

Easiest way to get into the 70's is to get a better short game.  Get putts/18 under 34 and try to get up and down at least half the time, including bunkers.  Most amateurs do not score better because they hit the ball 5-10 yards farther.  To make it real, how much closer can you hit a shot from 150 instead of 155?  I would say that stat is negligible.  However, how many more putts would you make if your chipping and putting improved, where in missed greens, guess the difference between hitting a 4 foot putt or a 7 foot putt, AND you are a better putter... no brainer... and practicing putting and chipping are always free!

Hope this helps.