Savage, Yes, you deserve to get some feedback on the 550. I won't argue that you can double charge or not charge at all with a 550 but so can you with even a single stage press. When you reload, you should concentrate on what you are doing. If you are distracted, you need to check all the cases in the shell holder to see where you are.
Being somewhat paranoid about squibs and double charges, I designed a light kit for my 550. Each time I push the handle forward to prime, an arm swings over the "just been powdered" case and a bright light is switched on. This allows you to see clear to the flash hole on an empty straight wall case. After a few loads, you can easily determine if a powder charge is light or heavy. It doesn't measure the charge, just gives you a visual. The 650 powder check station has about the same accuracy.
With the 550, you can insert or remove a case from any station. You can also use the press like a single stage or a turret press. No other Dillon press has this feature. Example: say you want to just size and deprime a batch of cases. The 550 will allow this because the shell holder doesn't automatically advance. Or how about when you do screw up and advance the shell holder without pulling the handle all the way down. No problem, you just reverse the shell holder one click. Try those operations on a SDB, 1050, or a 650. When I buy new cases, I get primed cases because they are cheaper than buying the cases and primers seperate. With the 550, no problem; just insert the primed case in station 2 and keep truckin'.
I ran into some primer feed problems with CCI primers. I called Dillon and their suggested fix was using Winchester primers. I had just bought a brick of a thousand CCIs and decided to try my own fix. I replaced the plastic primer follower rod with a rod made from brass tubing. The extra weight pushing down on the primers fixed the problem. I haven't had a primer feed issue since.
I once ran out of powder while loading some 223s. Too much concentration on the function and I failed to notice the hopper was empty. I thought about buying Dillon's Low Powder Sensor but after looking at it I decided to make my own. I used the Low Primer buzzer and made the following:
It works great for loading rifle when you only get a couple hundred loads per pound of powder. I never use it with pistol loading because the hopper will hold more than enough powder for a large batch of ammo.
I'm not saying the 550 is the best press in the world but it is exactly what I wanted after trying other Dillons and other brands.
