Dillon 550b primer bar modification

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Off and on, for month now, I have had some issues with the bar, which picks up the primer from the primer tube. On the return trip to place the primer, the bar "chatters" sometimes and hangs up. I take care to clean that area (blow air to clean it out), and use moly dry lube on the moving parts, especially the primer bar bearing plate. That's the black plate that sits under the sliding aluminum bar.

I've tried all sorts of things to elmininate the chatter and hang ups. I finally hit on a solution, and hope that it might help others with a 550b. It might even work on the 650 XL's.

The return spring for the bar clips onto a vertical pin/rod. The top end of the pin/rod stops against the head of a hex screw. The lower end of the pin/rod has a groove machined out to hold onto the loop at the end of the spring.

That pin/rod is a press fit in the hole that it's in. I tapped the pin UPWARDS a smidge, such that the spring is up against the bottom of the plate assembly, but not touching. It was MUCH lower before I tapped it up. Now, the returning bar is being pulled almost exactly along the same plane as the bar, and returns perfectly!

Out of focus picture, but hope that you get the idea:
dillonmod.jpg
 
It was probably broken all along or something. I've never had trouble with the bar. I just clean out the primer goo with a patch and hoppes #9 out of that little plate the bar rides on, and clean the bar off. I've never had to use moly lube or anything on the bar itself. Usually I load 800-1200 rounds before changing over to a different size primer, and I just clean it at that point.

-Mike
 
My solution to this was:

1) clean the primer slide with 0000 steel wool. After a while, the paint on the primer slide starts to wear off and it increases friction. So the 0000 steel wool will clean that up.
2) clean the primer slide, bearing plate, and press with rubbing alcohol and cotton cleaning patches
3) lubricate primer bearing plate with graphite

If your primer bar is still chattering or not fully retracting, simply bend the operating rod out slightly so that it puts more pressure on the plastic wheel on the primer bar.
 
The 550B primer system is a Rube Goldberg design at best. There are so many things wrong
with it that Dillon has refused to address it's criminal. Duke's attempt at providing an answer
to this problem is #10,431. All previous 'home brew solutions' for this POS design have failed
to address the fundamental bad engineering inherent in the design.
 
I must be lucky. My 550 has worked well for 20 years and all I do is keep the primer slide and cup clean. The only prolems I have had were caused by a worn nipple on the primer feed tube.
 
I must be lucky. My 550 has worked well for 20 years and all I do is keep the primer slide and cup clean. The only problems I have had were caused by a worn nipple on the primer feed tube.

How many rounds can you load before you have to clean it?

If you have had your 550 for twenty years then you must have put that technological break through Dillon
calls the primer track bearing (metal plate under the primer bar) on your machine? This was their only
attempt in the 25 years I have owned the 550 to provide some solution to the primer system problems
users frequently encounter.

Pathetic.
 
I just know that since pushing that pin up I've run 2500 rounds straight without a glitch. Prior to that change I was lucky to get 250 rounds between the bar sticking.
:)
 
I just know that since pushing that pin up I've run 2500 rounds straight without a glitch. Prior to that change I was lucky to get 250 rounds between the bar sticking.
:)

I'm not doubting that solution #10,431 has finally solved the problem... [rofl2]

What is causing the problem with the 'chattering' and 'hanging up' is simple, so simple that it's hard to believe that Dillon
couldn't see the issue the minute they put the press together. When you raise the shellplate and the primer bar is extended
there is virtually no support on the end of the primer bar and the stupid rod puts a lot of sideways force on the primer bar
itself. That causes the primer bar to cock sideways slightly in the primer bar housing. With any amount of dirt/grit/grime
that bar will stay in that position as the spring does not have enough tension to provide the torque needed to move the
bar forward. What Dillon needed to do is provide a positive return on that bar like they did with the powder drop (and
dump that stupid rod that moves/perverts the primer bar.) If they fixed that I could live with the stupid primer catcher
that does not catch and the primer rods which don't always feed the primers.

ETA: There is so much wrong with this design it is amazing it even works at all. Can you imagine what they were
thinking when they decided to do the depriming right over the exposed/open primer slide area? Freakin' geniuses
I tell you. And don't get me started on the idiotic primer catcher.
 
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I'm not doubting that solution #10,431 has finally solved the problem... [rofl2]

What is causing the problem with the 'chattering' and 'hanging up' is simple, so simple that it's hard to believe that Dillon
couldn't see the issue the minute they put the press together. When you raise the shellplate and the primer bar is extended
there is virtually no support on the end of the primer bar and the stupid rod puts a lot of sideways force on the primer bar
itself. That causes the primer bar to cock sideways slightly in the primer bar housing. With any amount of dirt/grit/grime
that bar will stay in that position as the spring does not have enough tension to provide the torque needed to move the
bar forward. What Dillon needed to do is provide a positive return on that bar like they did with the powder drop (and
dump that stupid rod that moves/perverts the primer bar.) If they fixed that I could live with the stupid primer catcher
that does not catch and the primer rods which don't always feed the primers.

ETA: There is so much wrong with this design it is amazing it even works at all. Can you imagine what they were
thinking when they decided to do the depriming right over the exposed/open primer slide area? Freakin' geniuses
I tell you. And don't get me started on the idiotic primer catcher.

Patriot, you must be a Hornady guy! I've had mine for a bit over twenty years and did have some issues with the primer bar that you guys have had. After polishing all working surfaces, lubing with a dry lube, and proper adjustment, it had worked very well. I do clean the residue out of it occasionally when it gets sluggish which isn't very often and of course, when changing primer sizes. Simple design that works pretty well.
 
Patriot, you must be a Hornady guy! I've had mine for a bit over twenty years and did have some issues with the primer bar that you guys have had. After polishing all working surfaces, lubing with a dry lube, and proper adjustment, it had worked very well. I do clean the residue out of it occasionally when it gets sluggish which isn't very often and of course, when changing primer sizes. Simple design that works pretty well.

I wish I was a Hornady guy! I've struggled with this press since 1986. I keep looking at it and think about doing a
design for it to eliminate that crappy primer system and sell it as an upgrade. If I made $10/unit profit I would be
filthy rich.

The press I purchased was a 550. They came out with the 'B' version a while later. I didn't reload much during the
years we were raising our three children so I lived with the shortcomings. Over the last few years where I have really
been giving it a run for it's money, those same shortcomings are freakin' painful.

When I bought the press there was no 'primer bearing plate' of whatever they call it. If you think the primer slide
sucks now, you should have been using it when it was riding on poorly machined aluminum. They also upgraded
the powder system, because unlike the primer slide, someone can get really hurt if that sucker sticks and drops
a really big charge of powder in the case being loaded. They did a pretty good job on the powder slide and I am
comfortable with the rest of the press. It has no more idiosyncrasies than any other and I personally like the
manual indexing. I can get into a real rhythm if the GD primer slide doesn't hang up. While I don't like having
used primers scatter across the loading area floor, I can live with that. Their dies are pretty good, their service
so-so, the warranty beyond reproach. I own a lot of Dillon stuff and if I didn't I would move to the Hornady
platform and sell the press. I am sort of locked in at this time and for the foreseeable future unfortunately.

I made a little fun of Duke's fix as I have seen so many of these home brew fixes, tweaks, and answers over
the years that I crack up each time I see another one. One day it's graphite lube, the next day it's sand this
or sand that, the next day it's move a pin, and so on and so on. It never ends because the primer system
is fundamentally flawed in it's design, period. Some folks are lucky and it works. Most suffer with it in one
form or another.
 
How many rounds can you load before you have to clean it?

If you have had your 550 for twenty years then you must have put that technological break through Dillon
calls the primer track bearing (metal plate under the primer bar) on your machine? This was their only
attempt in the 25 years I have owned the 550 to provide some solution to the primer system problems
users frequently encounter.

Pathetic.

I have the primer mod/improvement but didn't really need it. I keep a tooth brush on the bench next to the machine and give the system a scrub every couple of hundred rounds. It only takes a few seconds. I think the real problem with the system is soot from the decapping operation.
 
What my mod does is to set the angle of the pulling spring such that there is almost no side forces or vertical pulling on the slide bar.

The only way that you could get a straighter pull on the slide bar would be to attach the spring to the far side very end of the primer bar, and the other end to the frame. I looked at doing that but it looks like the round post/ram would be in line with that.

Other than the dry lube that should be on those sliding surfaces, I ran 2500 pieces without having to blow debris away or do any further tweaking.

If you don't have your pin set like mine now is, you should try this tweak and see the improvement.
 
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I must be lucky. My 550 has worked well for 20 years and all I do is keep the primer slide and cup clean. The only prolems I have had were caused by a worn nipple on the primer feed tube.

I haven't had mine anywhere near that long, but I've never had any trouble with it either. Most of the people I know with 550s also haven't had that much trouble beyond the occasional broken part or whatever.

-Mike
 
Bought my 550B used and initially had problems with the primer bar moving smoothly.... After inspection found slight dings/burrs on it that pretty easily stoned out.... Also had initial problems with the small stop screw that sets the primer bar travel so that the seating assy aligns to the hole in the loading plate.... Loctite fixed that.... Like everyone else I clean with alcohol wipes pretty regularly and change out the plastic tip on the primer tube when it gets worn (I start to see primer orientation problems).... Also like many I deprime/size on a single stage to keep all the crud out of my dillon and also to improve the "feel" of the press when I am loading (particularly for bullet seat/crimp potential problems)....

I keep two complete primer bar setups, one for small primers and one for large to help make changeovers quicker/easier....

Other than the initial start up stuff and what I would call regular maintenance I have had no problems with my dillon.....
 
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I've had mine twenty years and I called Dillon back then with help on a few adjustments and it is fine since. I also have to clean it every 500 rounds to insure reliability. Look at each individual problem as that.

I used to spill spent primers till I made sure the spent primer catch was opening and closing on every stroke, just a cotter pin adjustment.

There are a lot of things happening at once break them down and most are easy fixes.

Duke, I'm glad you found another potential problem and hopefully it will save someone a lot of frustration and the invention of a few new swears.
 
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I used to spill spent primers till I made sure the spent primer catch was opening and closing on every stroke, just a cotter pin adjustment.
I still spill some spent primers now and then. I find if I clean the primer chute now and then it reduces that. I might try to open up the holes for the cotter pin.
 
I opened up the holes and that helped. However, what really made the difference was tossing out the soft cotter pin, and replacing with a piece of music wire. Now, it never fails to pivot correctly.

M1911:1958438 said:
I used to spill spent primers till I made sure the spent primer catch was opening and closing on every stroke, just a cotter pin adjustment.
I still spill some spent primers now and then. I find if I clean the primer chute now and then it reduces that. I might try to open up the holes for the cotter pin.
 
M1911, since I adjusted the cotter pin, I dump about 3 out of 100 on the floor.

Either open the holes or adjust the cotter pin to prevent binding during the operation and then its primer nirvana.
 
I have the primer mod/improvement but didn't really need it. I keep a tooth brush on the bench next to the machine and give the system a scrub every couple of hundred rounds. It only takes a few seconds. I think the real problem with the system is soot from the decapping operation.

Yeah, I hear you. I can limp along for at best 500 rounds just brushing it off and wiping it the best I can
with the alcohol wipes, but after about 500 rounds it's tear down time and clean thoroughly. Their stated
time for throughput on this press must have been timed from all set up to the first 100 rounds and then
extrapolated for rounds/hour.
 
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Anyone have a problem with live primer's getting spit out? Never had that issue until I switched from Wolff to CCI. When I pull the handle back to deprime, sometimes one or two get spit out. Not sure where they're coming from. At the end of a loading session, I'm on my hands and knees searching the floor for live primers. I've taken it apart and cleaned it umpteen times. It's the correct primer tube (small), I've changed the plastic piece on the end 3 times and adjusted the height of the primer cup. Measured it exactly with calipers. Still does it. Drives me crazy!
 
Anyone have a problem with live primer's getting spit out? Never had that issue until I switched from Wolff to CCI. When I pull the handle back to deprime, sometimes one or two get spit out. Not sure where they're coming from. At the end of a loading session, I'm on my hands and knees searching the floor for live primers. I've taken it apart and cleaned it umpteen times. It's the correct primer tube (small), I've changed the plastic piece on the end 3 times and adjusted the height of the primer cup. Measured it exactly with calipers. Still does it. Drives me crazy!

In my experience this problem is always a worn plastic nipple on the primer feed tube. You can get into trouble (I did) by making adjustments on the primer feed system before replacing the nipple. If this is what you did, you have to return these adjustments to their original settings.
 
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