Dillon Priming Issue

Hello all,

I have a older Dillon 550 that has developed an issue with the primer slide....

Occasionally the primer slide will get stuck in the primer pickup (out) position.  A gentle nudge will typically loosen it so that it can travel to the priming location.  I have lubed it with dry graphite, cleaned off the lubricant, changed the operating rod and the return spring but it still feels like it is binding on something.

Any suggestions?  Will something like the UniqueTek "primer track bearing" help?

Thanks.

Jim

I used the UniqueTek and it helped, but eventually I replaced both primer arms and that made a big difference.  My unit is very old and had a lot of time on it.

I had the exact same problem as you describe. Get one of these

https://www.amazon.com/JW-Systems-Dillon-Primer-Bearing/dp/B01L9Q2TX4/ref=sr_1_1?crid=24YWCKOXH694A&dchild=1&keywords=dillon+550b%2Fc+primer+track+bearing+plate&qid=1586443632&sprefix=Dillon+primer+be%2Caps%2C242&sr=8-1

Works great and it feels smooth

+1 for the JW plate

I have had this happen before and it seems to be more of a binding issue than alignment - in my case anyway.  What I did was remove the primer assembly and primer slide bar.  After removal I manually worked the slide back and forth to feel the bind.  Finding that I opened up the clearance with a piece of 600 grit sandpaper on file - basically fitting the slide to the assembly.  Did this repeatedly only taking off slight amount each time to the slide and re-trying till it was running free.  Afterwards lubed surfaces with a very thin layer of machine oil.   I know they say not to use oil but I think if it is applied really thin as to not get in primer cup or primers its OK.

What I think causes binding is that the primer assy is soft aluminum and tightening the screws seems to cause some slight internal swelling on torque - so don't torque down too hard.

the JW plate does work very well.. bearing is probably overkill but whatever.

after cleaning up the slide a bit of dry moly or graphite works well.

the other thing that can cause an issue on the 550, is the little nylon roller guide for the arm.. they run all over the place( in and out) and can get stuck.. a small spring behind the roller will keep it in position.. we solved the issue years ago by adding a 6-32 round head bolt and lock nut behind the roller to guide it so to speak..

Greetings,

Why not contact Dillon?

They will probably send you the needed parts.

Cheers,

Dave

I had the same problem with my 550.  Got it for Christmas when I was 14 (1986).  It was sticking and giving me fits.  I had it on and off so many times that i pulled the helicoil out of the base.  I called Dillon and they sent me an entire new priming system including a new low primer sensor, and a plate that the new slide runs on.  No problems ever since.

Scott

Thanks gents,

All great suggestions.  I think I have a game plan and will report back as to my success (hopefully).

Jim

I have a 450 upgraded to a 550.  Tightening the screws that hold the priming system on made them bulge in the channel where the slide is.   Dillon said file those bumps off.  Worked for me years ago,  Still using it, and I don't crank those 2 screws down as hard,

David

I had to do the same thing as David said. Works great ever since I filed that bulge  off.

I sanded a little off the bottom of my sticking slide, reapplied graphite, has been good since.

David R wrote:I have a 450 upgraded to a 550.  Tightening the screws that hold the priming system on made them bulge in the channel where the slide is.   Dillon said file those bumps off.  Worked for me years ago,  Still using it, and I don't crank those 2 screws down as hard,

David

I did the same thing as this, as suggested by Dillon. They also suggested dropping a primer through the primer feed tube. They also said, after removing the primer slide, to put an expended primer in the cup and loosen the set screw. I put it in a vise, holding the primer cup assembly down and applied blue LocTite to the set screw and tighten it down. I let it dry and then reassembled. I also cleaned the plate the slide rides on and degreased it.

I occasionally clean the tube with a gun cleaning rod and patch. 

David

Hello all,

Following up....

I disassembled the priming unit and it was quite obvious that, yes, the channel that the primer slide travels in was "swollen" at the mounting screw holes.  Two minutes with a fine lug file removed the small bumps and the slide was free to move once again.  While I had it apart, I also replaced the primer track bearing with a new unit from UniqueTek (T1571).  The net net, the priming assembly functioned smoothly and effortlessly for a two hundred round test run of loading.

Thanks again for all of the advice.

Jim

I had the same issue caused by over-tightening.  I did file the bulges out and that seems ok for a while but it would still stick after 500 or so rounds.  Called Dillon and they sent me a new part.  Problem still exists.  I just have to pull apart every 500 or so and clean it out.  I have tried dry lube but do not seem to eliminate the issue.

If I can prevent any dirt from getting in the area it would solve the issue.  Maybe de-priming off of the press would prevent this from happening since that is the only source of dirt at this point.

Toz35m, you definitely have an issue somewhere in the unit..  how is it sticking.. Do you have a support plate under the primer slide?

I can load for a month on my 550s and not have any sticking

Jimmy,

The slide stays in the pickup primer position and with a little push to the right it goes back to where it should be going.  I do not have the extended support plate just the stock version.  once cleaned it works just fine.  I did pick up a used 650 and so I have been loading on that more recently.

The extended primer supports work the best..also look at you primer operating rod and the hole it sits in..if you slip the operating rod out and swivel it up vertically it should be straight in line with the primer stack. If not it may be bent or the hole it swivels in simply worn to the point where it is allowing the rod to push the slide sideways..sometimes a rubber band around the rod and hole will help or simply get new ones from dillon. The plastic roller that the rod pushes will allow the rod to push it inward. A.spring behind the roller or a 6-32 round headed screw behind the roller will keep it from going out of alignment. We have drilled and tapped for the screw on the primer bar before.. you have to remove the roller. We have even used a nut to lock the scew at a given distance.

Ideally the roller should not move around if the rod is straight and it's swivel hole correct and in proper alignment.. new parts.from Dillon may resolve the issue.

It is my understanding that priming system on 550 and 750 are similar or the same.  I'd appreciate confirmation, and I'll post my experience on the tread I started for XL750.  I don't have 550, have no experience with it, and hence can only rely on my observations with newly acquired 750.  I've been through about 6000 rounds on it by now, and made some modifications.

Jimmy,
You have both.  Are priming systems similar or same?  I.e. can you take everything from 750 and move it to 550, and vice versa. Does it work?

AP

Very similar. The operating rods are bent a bit differently but the principles of operation are the same.. the 550 unit is smaller than the 750. I'll see about getting some comparison photos of the pieces today.

550 on top 750 below.
750 larger and the primer seating arm is taller.to work on the 750

easy to see the size difference. you can see the 6-32 screw head on the 550 bar behind the roller..

jglenn21 wrote:
easy to see the size difference. you can see the 6-32 screw head on the 55 bar behind the roller..

  My fix is basically the same only I use a empty 22 case I cut the rim off and size to the space between the roller and the jesus clip. I let the rod float and don't use a rubber band. I don't have any problems with this setup either, the 2 rollers are pretty well lined up. I couldn't get my pictures working.
Stan