Re: Primer issues with Dillon 550B
I know you got more help here than you might be able to digest but I'll offer more as, on occasion, I have suffered some of the same problems. To be clear I have been using my RL550B for over 25 years and love this press. To start with re-read your manual several times. There are many importantdetails hidden in those instructions. Ab feel free to call Dillion. Their techs know this press and can help but most importantly they want to really help.
First is the shell plate. Tighten the main bolt then test the shell plate by rotating it through a full 360 degrees. It will be tight somewhere in its rotation so back the bolt out until you just fell no binding anywhere in the complete rotation of the shell plate. Then lock it down with the allen bolt on the ram (as pictured above). After a couple hundred rounds are loaded re-tighten the central large bolt and again set it with the allen bolt in the ram.
When installing the primer system do it with the press handle all the way down and compressed so the primer cup and punch extends then tighten the two retaining bolts. Release the handle and operate it so the primer bar has to move into position (full travel each time) and so the cup and primer punch extend into the shell plate. If you detect any catching of the cup on the shell plate loosen one of the primer system retaining bolts and push the system into alignment. Do not reload until the bar will travel and the cup will rise in the shell plate without scrapping or dragging on the sides of its hole in the shell plate. This is a fiddly adjustment! If there is any scrapping or dragging on the sides of its hole in the shell plate then the primer may flip sideways in the cup during delivery. After a couple hundred rounds you may have to go through this adjustment again. Over tightening the primer system bolts can tweak it out of adjustment. Once set the primer delivery should be fine for several hundred rounds.
Some addition checks: Is the little scoop that catches the de-primed primers free to move to catch the primer that just came out of the case? Its pivot is a cotter pin and it can cause it to not operate, dumping the de-primed primer into the mechanism. Also as I rotate the shell plate I use a hand on each side to assure the ball detent is really seated in the shell plate. Gentle, again.
When loading the primer system I fill the loading tube using a flip tray. I then stick the long plastic rod into the pickup end, place the other end on top of the press primer tube, stand the loader tube vertical and pull the retaining pin. The primers will fall into the press primer tube, followed by the plastic rod. The rod tends to keep the primers together so that they don't flip when entering the press primer tube. Then the long plastic rod goes in on top of the primers to keep a little pressure on them to assure the delivery mechanism works correctly.
When operating the shell plate to advance it, be gentle or you will throw powder out of the case on the table. Don't ham-fist operate the press. Smooth is the way.
As for lubrication on the priming system, I put a very light coat of powdered Teflon (Hoppe's) on the top of the plate the primer bar moves on. Anything else just attracts dirt. I use the Dillion grease on the ram and in the provided lube holes on the lever arms and pivots.
The RL550B is not perfect... nothing mechanical made by man is. You just have to figure out how to stay ahead to it and when to readjust it. Once you get that figured out the press is very easy to live with unlike other presses I have used.