Dillon 550b primer bar modification

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:
http://www.sebagosales.com/reload/dillonmod.jpg

Intersting fix.

Pretty sure current production bars are teflon coated, mine are on my newer press. Rub in
a coating of molybdenum disulphide dry powder (Molykote G) if you have it [non-tefloned bars] and it will run
smoothly for months. Otherwise, buy (they may give you a free one) a teflon coated bar from
Dillon if you have any more problems.

Same situation on the powder measure sliding bar.

Bill

Chatter on my 550 always was a indication that I needed to clean and then polish the silver primer slider with some very very fine sandpaper. Blowing it with air is not cleaning it. It gets a coating of **** under it that is very nasty and hard to remove. Need to use gun cleaning fluid.

Good thinking, Duke.
What are you loading in the photo? 357SIG?
My favorite round...

Have the same issue..going to give both a go.. Thanks Duke, Bill

You need to order "Primer Track Bearing part #14015 " its $ 3.69.

I had same issues as the rest of ya, once that was installed I've not had an issue one.

Almost forgot the link: http://www.dillonprecision.com/#/con...369/?viewImg=0

Quote:

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Originally Posted by warf73

You need to order "Primer Track Bearing part #14015 " its $ 3.69.

I had same issues as the rest of ya, once that was installed I've not had an issue one.

Almost forgot the link: http://www.dillonprecision.com/#/con...369/?viewImg=0

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going to do that too, but until I get a round toit, I will just make small adjustments to the thing..
I have taken the bar off, and polished it up almost mirror finish.. 600, 800, 1000 grit emery.. and played with the positioning of the spring pin, found a nice sweetspot..
Next on my list... order the part, and a new ball for the end of the handle.. Need it for another press I have..


Found the round toit... ordered a strongmount too...

Dillon will send the part for free if it's damaged.

I have the primer track bearing and mine still chatters at times. Seems to like a good cleaning every 1000 rounds or so. It is amazing how much gunk collects on the bottom the the primer bar. I wipe it off with a rag and go back to loading.
I may adjust the spring position however, sure can't hurt.

Yeah, that's 357 Sig being run. Made up 3500 for the summer practice shooting.

Haven't had a hiccup since making that pin adjustment, even with a horribly worn bearing plate. No lube, no needing to wipe and clean like before.

Ran a bunch of 357 magnums and 38 specials after the run of 357 Sigs. Ran so smoothly, I kept running until I ran out of cast boolits!

Good GOD, I ran so many primers! Primer boxes and sleeves everywhere!!!!

Can't wait for that group buy on the primer tube filler gizmo.

When ever I change primer size I give the area a real good clean and relube with some good oil (I have used dry lubes, but the last few time I have used some light machine oil). I am about to load up the last of my 38 brass and when I have done that, I might have a look at adjusting the pin when I pull it all apart for another clean.

Think the primer bar slides on the primer track bearing.The I have found that if it gets marred scratched etc call and they send a new one .The other thing when reinstalling the primer housing
don't tighten it up right away move the handle back and forth a few times first .This seems to center the primer bar .Then push like your priming a case
and finish tightening the two screws.The other thing is when people take the primer cup off the slide and clean it /don't take it off/ get some caned air .People don't compress the spring enough and it hits the primer orifice and messes it up

Oil will attract more dirt. Dry, properly centered slider (like stated above), wipe the exposed area clean before loading, will load well for a long time. If not you have another problem to be trouble shot.

I wonder how BullPlate lube would work?

I agree any oil, no matter how good a lube will attract the glass powder from primer
residue and make a nasty abrasive mess. Even Bull Plate lube.

Bill

Kind of off topic, but I deal with the primer residue by decapping on a single stage press, sometimes resizing at the same time. It adds a step, but I think its worth it to keep the primer gunk out of the Dillon's workings.

I recieved my new part,... and then took some powderd graphite, and rubbed it into the surface... it got even slicker.. so, I am going to look at the angles of motion throughout the stroke, and adjust the spring pin to the point where the bar will move the minimum amount up and down when the bar moves out to pick up another primer.
I also now have it mounted on a strongmount...which is really nice..