stop on Dillon 550x
- Thread starter dahermit
- Start date
How have you determined that...have you used strips of paper to determine the pinch points? Has the point where the shell plate platform stops/touches the primer slide made an indentation mark in the primer slide?
FrankenMauser
New member
I think it's supposed to be the primer slide. But I had my 550B mounted directly to a bench. The stop was the handle hitting the bench.
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Kevin Rohrer
New member
On mine, it was either when the handle hit the bench top edge, or when the press shaft buttons-out at the top of the stroke.
If you have ever removed the ram for a cleaning, you will find the when the shell plate platform is removed, the ram will drop down lower than it does normally. So I don't see the linkage as being the positive stop on the priming stroke.
How have you verified that...have you used strips of paper to find the contact point or have observed marks in the Aluminum (soft), of the primer slide?
How have you verified that...have you used strips of paper or some other method or observed a mark in the soft Aluminum primer slide where the hard steel of the shell plate platform contacts the primer slide?
dahermet said:
I simply looked, but the light wasn't great. I went back with a bright flashlight and looked more carefully. What actually happens is the shell plate platform depresses the spring-loaded primer-seating cup that surrounds the primer seating punch, and that cup is what actually makes contact against the primer slide, acting as the go-between for the shell plate platform and the primer slide. And yes, there is a round mark on the slide from that contact.
Using a very bright LED bore light, on my 550b, I can see that the primer cup bottom does not make contact with the primer slide and there is no mark that indicates it does. I can see that it does not (with some difficulty) from both sides. As a matter of fact, I can see one coil of the primer cup spring between the primer slide and the bottom of the primer cup when all the way down.
I have suspected that the actual stop (at least on mine), was therefore (if not the bottom of the primer cup) the primer cup spring, collapsing until the coils make contact with each other and serve as the stop. However, I cut one coil from the spring and stretched it, mounted it and found that there was still something stopping the ram other than the spring. So the mystery continues.
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Examining the primer punch and the primer cup, in order for your (I assume supposition) to be correct, the primer punch would have to contact something to cause it to stop. As I examine my press with no case or primer in the priming station and press the handle back (as if priming), the handle stops. When I examine a primer cup and a primer punch, I see that the priming punch when sitting as it does in the primer cup actually will slide through the primer cup. So, it cannot be causing a positive stopping motion.
Going the extra mile for Dahermit
On the press there is a casting called the cartridge collection bin bracket. That casting has a clearance recess cast into it with a radiused bottom and the mouth of the recess is open toward the front of the press. At the top of the handle stroke, the handle slips into that clearance recess, but does not touch down in the bottom of it. Rather, it stops about 1/16 of an inch short of reaching that radiused bottom of the clearance recess in normal operation. If the handle went all the way to the back of the recess and touched down, you would soon find a wear mark on the handle where they meet. Mine does not have one.
The above is true with the primer slide group fully assembled. So, I did the following:
1. I took my 3/32" hex wrench and removed the primer punch, primer seating cup, and its spring. Nothing on the bar. I pushed the handle up and it went all the way back into contact with the radiused bottom of the clearance notch.
2. I put only the punch back into the slide. The handle still made it all the way back into contact with the radiused bottom of the clearance notch.
3. I put the spring over the punch. The handle still made it all the way back into contact with the radiused bottom of the clearance notch.
4. I removed the spring and put only the primer seating cup, leaving the punch in place as its guide. Now the handle stopped reaching all the way back into contact with the radiused bottom of the clearance notch, just as was the case with the fully assembled slide.
So, in addition to the circular mark on my primer slide, I have proven the primer seating cup is, indeed, the stop. If I remove it, the handle still stops, but it is about 1/16 of and inch further back because what is stopping it has changed from being the primer seating cup sandwich to being the bottom of the casting's clearance recess.
If your primer seating cup is not what is stopping your press, look at the catch bin bracket casting and look for a wear mark on the handle of your press where it is touching down there. That isn't supposed to be happening, as it shortens the maximum primer punch reach up into a case primer pocket. Only stopping on the primer seating cup produces the correct full reach of the primer punch. You may have screwed the casting to the bench too far foward and need to move it back a little.
On the press there is a casting called the cartridge collection bin bracket. That casting has a clearance recess cast into it with a radiused bottom and the mouth of the recess is open toward the front of the press. At the top of the handle stroke, the handle slips into that clearance recess, but does not touch down in the bottom of it. Rather, it stops about 1/16 of an inch short of reaching that radiused bottom of the clearance recess in normal operation. If the handle went all the way to the back of the recess and touched down, you would soon find a wear mark on the handle where they meet. Mine does not have one.
The above is true with the primer slide group fully assembled. So, I did the following:
1. I took my 3/32" hex wrench and removed the primer punch, primer seating cup, and its spring. Nothing on the bar. I pushed the handle up and it went all the way back into contact with the radiused bottom of the clearance notch.
2. I put only the punch back into the slide. The handle still made it all the way back into contact with the radiused bottom of the clearance notch.
3. I put the spring over the punch. The handle still made it all the way back into contact with the radiused bottom of the clearance notch.
4. I removed the spring and put only the primer seating cup, leaving the punch in place as its guide. Now the handle stopped reaching all the way back into contact with the radiused bottom of the clearance notch, just as was the case with the fully assembled slide.
So, in addition to the circular mark on my primer slide, I have proven the primer seating cup is, indeed, the stop. If I remove it, the handle still stops, but it is about 1/16 of and inch further back because what is stopping it has changed from being the primer seating cup sandwich to being the bottom of the casting's clearance recess.
If your primer seating cup is not what is stopping your press, look at the catch bin bracket casting and look for a wear mark on the handle of your press where it is touching down there. That isn't supposed to be happening, as it shortens the maximum primer punch reach up into a case primer pocket. Only stopping on the primer seating cup produces the correct full reach of the primer punch. You may have screwed the casting to the bench too far foward and need to move it back a little.
Thank you for you efforts in investigating my Dillon/priming concerns.
I should have specified that my center of interest involves only the large primer priming system, not the small. And also note that there may be some minor but significant variations between your press and mine. It is also notable that my press sits atop of a homemade (heavier gauge than a true Dillon), not bolted to the bench. I have also done due diligence in making sure the handle does not touch anything including the catch bin bracket.
Today when swapping back to the small primer set-up I noticed a very small "divot" in the right side of the primer slide (large), adjacent to the primer catcher. I also noticed that on the small primer slide, I had at some point ground a small "v" in that same area. I suspect that at some point in the past, I discovered that there was some interference at that point and dealt with it and possibly successfully. The problem could be that I just cannot remember things that well anymore, being 77 years old with memory problems due to significant White Matter being observed on an MRI. In any event, I have switched back to using small primers and don't know when I can relive (grind a "v") and test the large primer slide.
Again, I am grateful for you investigative efforts on behalf of my query. When I get around to shooing up any large pistol primed cartridges (it could be some time) I will test out the altered large pistol primer slide and report if the problem was indeed that interference...if I can remember.
Nope...different animal.