I've used a Forster Case Trimmer for over 45 years and it still works just fine.
The Forster Trimmer only needs a "guide" (not what they're called, they're possibly called "collets") for the caliber of the cartridge case you're going to trim (a .224-inch "guide" for your .223). The "guide" or "collet" is positioned between the trimmer's blades and fits inside the case mouth to "center" the case on the trimmer in order to get the job done.
You can also buy other accessories to use with the Forster Case Trimmer if you wish to get really serious about accuracy. I have accessories for doing the inside & the outside neck turning of the cases, but never use them anymore.
If you get another caliber rifle, all you need do to trim the necks on the new caliber is get a "guide" for that caliber and insert it into the trimmer on the Forster Case Trimmer and you're all set to trim the new caliber cases.
Those "guides" are very inexpensive... maybe $1.25 or so each, but I haven't bought one for many, many years, so they may be slightly more now.
To insert them, you simply loosen a allen-headed screw, remove the other "guide" that is sitting between the trimmer blades and insert the new "guide" in the vacated guide hole between the trimmer blades, re-tighten the allen-head screw to hold the "guide" in place and that's it. Then you will need to adjust the timmer for the new case's length. Then you're all set to start triming the new caliber's cases.
The Forster trimmer also has a micro-(screw) adjustment once you've set the trimmer for the case length so that you can make tiny adjustments for case length/trim length if you're not triming quite enough brass off the mouth of the case or if you are triming a bit too much off the mouth of the case. It's a very hand, precise adjustment which is what you need when you're working in a few thousandths of an inch on case length.
The only item you'll need to trim the cases is a "guide" for each caliber you wanna trim... and right now, you've only got one caliber... the .223 which uses a "guide" measuring .224 inches in diameter.
You'll also need a deburring tool for inside & outside deburring of the case mouth once it is trimmed to the proper length. But that is something you'd need regardless of the brand of case trimmer you buy.
The Forster Case Trimmer screws down (4 small screws) to the top of your loading bench or you can do as I did and mount it on a piece of 2 by 4 and drill 2 bolt-holes in the 2x4 with which to run bolts through the 2x4 and through the bench-top, then "lock" it down by add wing-nuts under the benchtop to lock the trimmer on the 2x4 into place.
Then you can get an adjustable aluminum holder which holds an electric screw-driver in a V-shaped form and align and use the electric screw-driver like a tiny lathe motor to turn the trimmer. However, you'd only need that if you were doing hundreds and hundreds of cases which is doubtful at this point in your reloading. You can also get the adjustable aluminum holder if you find turning the trimmer handle is a big chore.
Or... you can merely use the handle that comes with the Forster Case Trimmer to do the turning for both the case trimming and the deburring if you have a deburring holder set up on a 2x4 as well. Or you can deburr by hand, one case at a time... turning the deburring tool first one direction to do the inside of the case mouths, then turning the other way to do the outside case mouths.
But don't worry or get confused... once you see the equipment and hopefully, someone will explain the basic operation to you, you'll be all set to begin.
I'd suggest you attempt to find a "reloading mentor"... someone who is an experienced reloader to sit with you for first several times you do some reloading and offer his expert advice... the "do's" and "don't do's" so to speak.
My set up is like a tiny machine shop with an electric screw-driver doing all the work and turning the timmer as well as the deburring tool... but you don't need to get that "fancy".
Good luck in your new "adventure"... I think you'll find you enjoy doing your own reloading... and you'll save a lot of money over buying factory-loads, trust me!
Strength & Honor...
Ron T.
