If I were you, I would go for the 3 die setup and this is why.
I started out reloading 45acp with a separate seating and crimping die because this seemed to be the internet consensus and not having a reloading mentor I didn't know any better. After loading a couple thousand rounds I began to wonder if I could seat and crimp in the same step and save a little work. I reload on a turret press so I turned the combo die down until it just removed the bell from the end of the case and the round would plop into the barrel. I have loaded another 7-8 thousand rounds since then without a problem.
It is my opinion that if you carefully set up your dies and forget about "crimping" you can probably load 9mm with a combo seating taper crimp die. If you can't make it work you can always buy a separate taper crimp die.
I think for the sake of new reloaders the taper crimp die should be renamed bell removal die.
I have a couple of 9mm factory rounds on my desk right now and I'll be dammed if there is any crimp in either one. One of these rounds is a hollow point self defense round that I use in my carry pistol. I have always wondered if you get setback from repeated chambering, so I did an experiment where I racked it in from a 1/2 full magazine 20 times and measured the length after each time. Guess what, no setback. Neck tension holds the bullet in place no "crimp" is needed.
So give it a try! A three die setup will may well save you 10,000 handle pulls in the next ten years.
By the way. I just started reloading 41 magnum and 45 colt about a year ago and this advise definitely does not apply to revolver cartridges that use a roll crimp. Those are a whole different ball game.
Bob
That's actually a really good post Bob ... and you closed well with that last paragraph although not all revolver cartridges require a roll crimp imho. I roll crimp when reloading big hand cannon fodder and/or 44 Mag loads for my 1894P and Redhawk combo. And I roll crimp most cast boolit loads. But I taper crimp fmj and tmj loads, especially those with cannelures. JSPs, GDHPs, etc., in 357 Mag ... those get taper crimps in my presses.
There is definitely an art to dialing-in a combo seating/crimp die to do both steps properly with one pull of the handle. It requires a consistent stroke of the handle, a good feel for your press and a careful setting-up process and tightening-down of your dies complete with set screws to avoid any and all potential for shift if you are running large batches.
I almost never run smaller batches than 100, usually more than 100, unless I am working-up a load to meet a specific need before running a big batch or when trying to match factory ammo performance ... again, before running a big batch.
One thing I have found over the decades is that the crimp has a big time affect, huge effect, on performance. You know, like they say football is all about offense, defense and special teams .... when, in fact, it is more about leadership, talent, heart, hard work, preparation, strategy and execution. Practice makes perfect. Likewise ballistics is about many things (once you remove the human element from the equation) but mainly platforms, powder, primers, pills and assembly. Each element multi faceted.
Proper crimping is an art, a skill, and knowing which crimp to use when and on what and how much is truly a learned skill.
As you alluded-to, one does not use the same crimp on a bolty specific 6.5 Creedmoor cartridge that one might use on a 454 Casull revolver cartridge just as one would not use the same crimp on a semi-auto necked-down magazine-fed cartridge that one might use on a straight-walled tube fed levergun cartridge.
Think about it. When I do it comes to mind that I probably have 8-10 very specific crimps, in my repertoire, that I might employ on a variety of difference loads ... reloaders rarely think of it in those terms but I'm sure most of us here could make the same claim. You've got three basic roll crimps, heavy, medium and light, and three basic taper crimps, heavy, medium and light, then, just off the top of my head I have a deep roll I use in grease grooves with certain coated cast boolits, another type of roll crimp I use for WCs seated to just below case mouth depth, another what I call half-light taper I use on TPJs and plated bullets (to prevent skinning upon sending) ... and so-on and so-forth.
Taught all my kids to reload years ago .... only my Son grasped seating/crimping in one stroke. The girls never could.
ETA: I had to snicker in agreement that a taper die could easily be construed as a "belled-mouth closing die" ... but it doesn't just roll off the tongue. lol
