I load 9mm, .38 special and .357 magnum and .44 magnum in a Lee Pro-1000 progressive press, when I started out I was concerned about the reputation of progressive presses I heard from old-timers on "Teh Intarnet" who said a single stage was the best way to go because you don't ruin as many rounds starting out.
Truthfully this is good advice but after only a few reloading sessions you will want speed
AND good ammo. Loading straight-sided pistol cases is so easy a child could do it.
The single-stage press has a single station above the ram to hold a single die. You need to do a batch process to make ammo. Take a reloading tray of 100 or 200 or how many you want to do at once. Manually put in and take out cases to resize and deprime. Next, use a manual handheld priming tool to prime your brass. Next, remove the resizing die you just setup, screw in the expander die. Expand each of the cases you just resized and dump powder in each case (IF you have a powder-through-expander die, otherwise, powder dump is a seperate step!) Next, remove the expander die and setup the seater die. Now manually load each powder-filled case, seating a bullet in each one.
That takes 5 steps to get one round of finished ammo. And you don't have ANY finished ammo until you complete the process, just stuff in progress. So if you get interrupted you have half-finished stuff sitting there.
A turret press is a good compromise between a progressive and a single-stage. It usually takes a circular turret (which are quickly removable and interchangeable) and mounts all of the dies on one turret. You set up each die correctly. Then they get locknutted and never need messed with again, if you have a spare turret for each caliber which is the BEST WAY to do this if you are loading multiple calibers.
Now, you manually put in a case. Pull handle to resize/deprime and then prime. Turn turret (or some auto-index the turret for you). Expand/powder dump. Turn turret. Seat bullet. Round is done. Now, each round is finished individually assembly-line fashion. Still takes 3-4 pulls of the handle to make one round.
Progressive combine the turret press' die handling (turret plates that contain all the dies, making interchange quick) with the ability to process multiple cases at once.
You load cases one at a time or have a case feeder. Pull the handle three times, a new empty case is loaded each time, then once the press is full, each pull of the handle ejects a finished round. You wind up with cases staged around the press in various stages of completion depending on which station it is in. Sounds complicated, but it really isn't. It's most like an assembly line there is. At any time you can stop the process by withholding new cases at the start, then a few pulls of the handle, the press is empty. You can make 300 rounds per hour on a Lee progressive, I know a guy who gets 450 RPH+ on his Pro-1000...
http://ohioccwforums.org/viewtopic.php?t=16128
The Dillon guys say they can go faster.
I recommend anyone who is loading only a few calibers of pistol, no rifle, to investigate the Lee Pro-100 progressive. Sure they are not a Dillon. But they
DO WORK and work well, within their limitations. I wouldn't want to run 10,000 at a time on a Lee Pro-1000 but for running a thousand at a time they work great for me.
As I have said on other boards, some of us are perfectly fine with the Sears lawn mower on sale, we don't need to spend the cash to buy a John Deere. That's not a dig on Dillon, it's just that if you are not running a machine hard enough to justify the more expensive "commercial" brand then a less expensive solution is OK.
If you are thinking about loading any rifle or are not comfortable with a progressive, a turret press is going to be "stronger" and allow rifle reloading. It is a bit slower but you have more control over each round. The lee classic cast press setup is a good deal.
A Pro-1000 brand new setup for one caliber is $130. If all you are loading is .38/.357 and 9mm, that's good. They both take the same size case feeders and same size primers. All you need to swap is a different shellplate (9mm is #19, .38/.357 is #1, about $12) and a 3-die set of Lee carbide dies ($20).
If you are loading on a turret or single stage, the Lee dies come with the appropriate shell holder for use in those presses. I really like Lee dies.
You need a powder check scale. The Lee scale is cheap, it works, it's accurate but slightly finicky until you get used to it. A set of inexpensive calipers is nice to have too. I recommend a tumbler as soon as you can get one because clean brass feeds better in the gun and in your dies and it just looks nice.
Search eBay for the good deals.
Good luck and happy loading.