Shak3s1977
Shak3s1977
1 post
Joined March 2018

550 primer seating problem

I purchased a new 550C in November last year. I have loaded about 500 rounds for 38 specials and had no problems getting primer depths of .005-.007 . I loaded 100 more the other day, and they were going good. Then I started getting higher primer seating. They were either flush or .001-.002 depth.

I stopped and found a spent primer under the shellplate. Removed it and figured it was keeping the ram from going all the way forward. After removing it, my primers are still not seating deep anymore.

I looked in the manual and it states the primer cup height should be between 1.215-1.220. Mine measures 1.208. I've tried adjusting it but it doesn't appear to be adjustable. Also the primer cup is really scratched on one side. I'm guessing is scraping the shellplate?

Is the primer cup height adjustable, or did I break or bend something? I'll try to post a picture of my primer cup. I'm guessing it shouldn't look like this. Any help would be greatly appreciated.

https://imgur.com/gallery/BghEJ
jforwel
jforwel
76 posts
Joined November 2007

RE: 550 primer seating problem

First, the primer cup has a small set screw for adjusting the height. Take out the slide bar, and using a spent primer in the cup turn it upside down and press down on your bench. First loosen then re-tighten the set screw.

Second, try re-adjusting the primer slide with the ram all the way down and the primer cup through the hole in the shell plate.
dillon
Administrator
dillon
3,222 posts
Joined July 2007

RE: 550 primer seating problem

Push down on the edge of the shellplate between stations 2 and 3. If it feels springy, then the shellplate bolt needs to be slightly tighter.
Next, check the left hand screw that secures the roller bracket #14281 to the underside of the platform. If it has backed out, the head of the bolt stops against the top of the primer slide, preventing primers from being fully seated.
The other possibility is that the lot/brand of primers has a higher anvil than the last, and is more difficult to seat.
k38
k38
4 posts
Joined April 2018

RE: 550 primer seating problem

What is the parts number of that screw? Also, I'm puzzled by the identification of the roller bracket as #14281, since that's the PN for the entire primer slide assembly. The roller bracket assembly is #14280. I'm having primer problems too, and might want to try this, but I don't quite understand.
k38
k38
4 posts
Joined April 2018

RE: 550 primer seating problem

jforwel--

I called Dillon and the tech said there was no way to adjust the primer cup height. Was he wrong?
jforwel
jforwel
76 posts
Joined November 2007

RE: 550 primer seating problem

k38, I once had a problem with primers not seating deep enough and called Dillon about it. I was told to take the primer bar off the machine, loosen the set screw that holds the cup and punch in place and with a spent primer in the primer cup turn it over on my bench, press down so the cup and primer are flush on the bench and re-tighten the set screw. That solved my problem, which was that over time the primer cup had slid up higher than it should be.

A third hand could be helpful here as the cup spring is quite strong. Hope that helps.
Currently
Currently
21 posts
Joined September 2014

RE: 550 primer seating problem

^^^^^^^^^^^^^

Now that is an elegant solution!
jrieder
jrieder
1 post
Joined February 2013

RE: 550 primer seating problem

I have been using my 550b for some years now and suddenly in the middle of a batch of reloads I began to experience the primer not being seated into the case well enough to rotate the plate to the next position. I have read many complaints regarding this with as many solutions. I have changed out the primer slide, adjusted/replaced the cup and plunger without success. I do have rare success 2:10 where the primer seats well but that ratio is not good. Dillon must be aware of this issue and what a 'legitimate' fix is to return me to completing the loading process. I did submit a callback request and was told it could take up to an hour for a reply. It is now sunday and monday is a holiday...so should I expect a reply sometime next week?? Hoping for some clarity on the 'actual' problem and a fix designed to remediate. Regards.
tet301
tet301
32 posts
Joined February 2016

RE: 550 primer seating problem

From your description of the problem, erratic primer seating, I suspect the culprit is the height of the primer cup assembly, which may have gotten gunked up or just has a tired spring. As has been written in this segment, and others in the forum, if THIS turns out to be the culprit, the assembly must be removed from the slide, cleaned and lubricated and then fit back in to the spec height of 1.215 to 1.220 inches. Look closely at the spring. Springs sometimes just get tired and no longer fulfill their function. It's such a small part of the machine, but the source of many problems. I would also be interested in knowing if this works or if I'm (as my bride tells me) full of poop.

Best

Terry
dahermit
dahermit
24 posts
Joined October 2007

RE: 550 primer seating problem

" Look closely at the spring. Springs sometimes just get tired and no longer fulfill their function."

Not likely...if the primer cup spring became weak, the primer cup would not push the primer cup up into the shell plate. The primer cup spring has nothing to do with how high the primers are or are not seated.
bill_reed@epbfi.com
bill_reed@epbfi.c...
3 posts
Joined June 2020

RE: 550 primer seating problem

I find the stem and cup need to be seen too from time to time anyway. Another source of problems is a powder spill. Ball like powder will migrate into the priming system. I have a small Harbor Freight bench vice that works very well holding everything together during adjustment.