I know everyone has their own way of doing it but this has sped up my brass prep. Just sharing.

I've had my Dillon 550b for 12 years and just recently got tired of the 223 brass prep chore. It would take a long time just for small batches of brass. Just really took the fun out of shooting because I knew I would have to process the brass to shoot more.

This was my process previously; I'd prep on one toolhead and then load on a different toolhead.
I'm using range pick up brass so I FL resize and trim every time as well as swage the primer pocket. I use range pick up brass to save money

Station 1: universal decap
Station 2: empty
Station 3: Dillon FL resize/trim die, Dillon 1200 trimmer
Station 4: empty

Then I would take the brass to my Lyman case prep center where I would chamfer and deburr, one by one.
Next I would take those cases and run them through the Dillon Super Swage 600, one by one again.
Then tumble the lube off and switch tool heads to load.

My hands would be tired, my back would hurt, and I'd have the brass loaded in no time and the process of brass prep would need to restart to keep it fed.

I decided to try the Lyman M die and Swage It on my Dillon 550.

And it has sped the entire process up substantially. I'm basically only touching the brass once (maybe two times) throughout the process.

New Process:

Station 1: Universal decap die, Swage It on the down stroke. I know all about the Swage It's warranty voiding magic and I accept the risk. If I break anything, I will just buy a replacement as I understand the risks with the Swage It and do not expect Dillon to cover it when they expressly say they won't.
Station 2: Empty
Station 3: Dillon trim/ FL resize die, Dillon 1200 trimmer
Station 4: Lyman M die. The Lyman M die sets the case neck back to proper neck tension since the Dillon FL die undersizes the neck/mouth. Also the M die can be set to provide a slight bell to the case mouth for helping seat flat base bullets or just to ensure the sharp trim edge doesn't scrape the bullet on seating. The M die was too tall to be next to the trimmer so I precisely removed the adjustment knub on top of the die (with the die clamped in a vice and using a sawsall). Now the die fits beside and under the trimmer and I still have enough room to adjust the amount of flare the die provides to the case mouth.

Then tumble the lube off, reinstall priming system and loading toolhead. Ready to load. Basically I'm saving myself the separate steps of chamfer, deburr, swage. I tried to time myself and it saves about 30 minutes per 150 pieces of brass, give or take. Shit adds up when doing 1,000 or 2,000 piece run.

I did a pretty extensive test (for me) of 100 rounds total of the old brass prep way vs the new way, as well as checking crimp differences using a Lee Factory Crimp Die. I prefer to use a FCD to close the slight bell on the case mouth as a result of using the M die.

I found no discernable accuracy difference at 100y in the brass prep method or using a heavy crimp vs no crimp. But I did see that my SD's were halved when not using the crimp die, down in the single digits over 10 shots through an AR with mixed brass. Some of the best SD's I've ever had with an AR.

I am not saying this is the right way or only way. Just the way I do it on a smaller Dillon 550 press for processing a lot of 223 brass with acceptable results.