Primer cup hitting the bottom of the primer feed on my 550.

[Canman]

This is what causing my primer feed to jerk and throw the primer. Does not do it every time but enough to warrent a fix. It almost looks like the primer cup is tilted or bent to the right. Any easy fix or just give Dillon a call?

[leewongfei]

It probably is bent/ not on straight. Those things can be a pain in the @$$ to get on correctly. I ended up reseating both of my primer cups and the problem went away. You could use the press to do it, but i found that my nylon bench vise had an opening just big enough to fit the cup, so i put it in the vise and tightened it up that way.

Edited March 26, 2014 by leewongfei

[dillon]

To get a better idea of the cause, remove the operating rod, unhook the return spring from the primer slide. Pull the handle down on the machine, and leave it down. Now slowly pull the primer slide rearward, and see if you can feel when it binds.

This will help narrow the possibilities.

[benos]

550 Priming Assembly Adjustment Notes:

• Thoroughly polish frame, wherever priming slide touches it, with green Scotch Brite. (Approx. every 3000 rounds)
  
• Wipe off Primer Slide with solvent or alcohol. Leave it all dry.
  
• At rest primer slide adjustment: Set so that one primer, dropped down the tube, goes all the way into the Primer Seating Cup, 10 times in a row.
  
• Angle of Primer Slide Operating Rod (13869) - Release rod from rollers and swivel it 180º so it's pointing straight up - it should be parallel with the Primer Housing Shield, or maybe outward "a little"; it should not be "inward" at all.
  
• Be sure both screws (14530) that tighten Roller Bracket Shell Platform (14280) from bottom (to the Shellplate Platform) are tight!
  
• Make sure Priming Seating Punch Assembly is fully bottomed out before tightening screw (13996): Measured from bottom of Primer Slide (13920) to top of seated Primer Seating Cup (13284/5), dimension should be between 1.125 - 1.220 inches.
  
• Be sure Priming Operating Rod Bracket (13887) is adjusted so it's within a few thousands of an inch from the top of frame/Toplhead.
  
• Be sure the plastic tips of all your Primer Pickup Tubes and the plastic tip on the bottom of the Priming Magazine are seated fully against the tubes.
  
• Grease the short end of the op-rod where it inserts into the bracket clamped around the primer shield.
  

[Cavy]

I had this happen on mine recently. Take the slider bar off the press and loosen the set screw in the side of it to release the primer cup and spring. Clean the underside of the cup and the shoulder of the shaft. Mine had debris in there causing cup to sit crooked. then it would contact the wall of the primer tube base as it tried to return. Reassemble the cup assy. and check to make sure it sits square to the bar. Mine has been working great since cleaning and did not require any parts.

[Canman]

Thanks to all the replys. I'll give them a try tomorrow.

[Canman]

Well I gave it all a try. It helped but the primer cup still comes into contact with the right side of the primer housing 20263. I loaded about three hundred rounds with no problems. Still trying to track down the cause.

[njl]

Well I gave it all a try. It helped but the primer cup still comes into contact with the right side of the primer housing 20263. I loaded about three hundred rounds with no problems. Still trying to track down the cause.

It really shouldn't be able to do that if it's properly assembled. I've found reinstalling the primer cup on the primer slide to be incredibly difficult to do properly (i.e. not canted). Take it back apart and put it back together again, using the press (with the shell plate between stations) to compress the primer cup spring while tightening the set screw.

[Canman]

I'll try it a couple more times. Have not tried between the stations yet. I just lined it up with the hole in the shell plate and compressed it. I am thinking my primer housing might be out of spec some how.