I have cut a few mold cavities. All my mold making efforts in recent years have been no lube groove (NLG) style. I have several good profiles for my 327 Fed, several for my 7 TCU, a couple of 30 cal and some heavy 35 cals. Photos below are more or less in order with newest first.
For Christmas, I got myself a four jaw independent chuck for my 7x14 mini lathe to improve my precision when making my own molds. I have had pretty good luck using Lee blank 2 cavity aluminum molds and a simple D reamer made from W1 drill rod. Just buying a few Lee blanks (
https://www.titanreloading.com/lee-p...nk-bullet-mold) will let you focus on the important part, cutting cavities. I have gotten some really good finishes by pre-drilling a hole and then running the D reamer in at a low speeds with plenty of lube. And a single NLG D-reamer can be good for a whole range of final bullet lengths / weights.
If you are thinking about making boolits for the 9mm, I would caution you that cast in the 9mm can be tricky. I recommend that you plan on powder coating as it is very likely to decrease the effort needed to finding a solution that does not result in barrel leading. Use of powder coat also allows use of a NLG profile. Going this way greatly reduces effort and improves you chances for happiness with a do it yourself mold.
As someone who had to fight hard to get cast to work in the 9mm, I will say that the Lee 120 TC profile is popular in 9mm by those who have achieved success because it just works.
Speaking as an amateur machinist (me) to a real machinist (you), I would recommend a profile similar to a Lee 120 TC, but with a flat base and no lube grooves. Below are links to a couple of accurate molds that give you an idea of the bullet dimensions that should get you close:
http://www.accuratemolds.com/bullet_...35-117ZR-D.png
http://www.accuratemolds.com/bullet_...35-125EZ-D.png
Now, back to the "9mm is tricky" stuff. If you read up on the subject you will find the most important point is "Fit is King". Undersized cast bullets is probably the biggest problem people have with the 9mm. And I am talking undersized after the bullet is seated in the case. The standard expander plugs leave the case ID too small and the case will size down you bullet during seating. If you have a standard expander plug, just plan of making a custom expander plug the will open up the case to the right ID (generally 0.001" to 0.002" under bullet diameter) for the full depth needed when seating the bullet. Now for the bullets themselves, generally you will want your cast bullets as large as possible and still be able to pass the plunk test with a dummy round. And it is a whole lot easier to size down bullets that are 0.003" oversized than it is to go back an rework a mold to increase your "as cast" diameters.
In support of the above, I recommend you pick your general profile, and turn a dummy bullet or two out of something no softer than aluminum. First drill & thread a through hole in 10-24 or 10-32 so you can easily pull it out of a case and so you can easily re-mount it in a lathe. Start with an OD of say 0.358". Seat it in a sized and lightly flared case (caution - headstamps do matter and some brass is thicker than others). Run it through you seater die if needed just enough to remove any remaining flare. See if it will freely slide into you chamber and "plunk" into the fully chambered position. If it does not plunk, figure out why. It could be the case is too big, or you could be getting bullet contact up in the throat. If you have a throat problem, either increase seating depth or remove bullet material as needed to fix it. If you get 0.358" to "plunk," this is what you should try for in way of finished bullets. If 0.358" is too snug, try 0.3575". Repeat as needed to find what diameter works in your gun. If you have more than one gun, check out all of your guns to see what will make them happy.
Lets say you find that 0.3575" is your largest size to pass the preliminary plunk testing above. I would actually shoot for as cast bullet diameters of around 0.358". The PC will add a little diameter, but bullets seem to work better when sized down some. In my opinion, sizing down 0.002" or 0.003" is better than anything under 0.0015".