Dillon SDB primer seating problems

[Catfish]

Google Fu failed so here goes:

I'm loading 9mm with mixed brass and Remington small pistol primers. Some of the brass is commercial, some is crimped, my problem does not follow this.

My primers don't always seat fully. Most of the time they're seated a perfect .001" like normal but a few in every batch are flush or even proud of the base. When I seat the bastages I'm pushing the press arm hard enough to move my bench around, half afraid ima break something. As a workaround I just run all my loaded rounds through an RCBS handheld as a post process. And every damned one of them seats perfectly with that tool. I'm tired of squeezing and I need help.

I recently switched from a red press where everything is adjustable to a blue one where nothing is adjustable. I feel like I switched from Android to Apple. How can I fix this?

 

[Toprudder]

Google Fu failed so here goes:

I'm loading 9mm with mixed brass and Remington small pistol primers. Some of the brass is commercial, some is crimped, my problem does not follow this.

My primers don't always seat fully. Most of the time they're seated a perfect .001" like normal but a few in every batch are flush or even proud of the base. When I seat the bastages I'm pushing the press arm hard enough to move my bench around, half afraid ima break something. As a workaround I just run all my loaded rounds through an RCBS handheld as a post process. And every damned one of them seats perfectly with that tool. I'm tired of squeezing and I need help.

I recently switched from a red press where everything is adjustable to a blue one where nothing is adjustable. I feel like I switched from Android to Apple. How can I fix this?

With a 550, it is possible that the shell plate is not tightened down as much as it should be. When I replace the shell plate, I tighten it down until you can’t turn the shell plate, then back off 1/8 turn. I’ve never had a problem seating primers when I do that. With an SDB I’m not sure how similar or different it would be from the 550.

 

[Clicker]

I'd pull the entire primer unit out of the press and clean every part on it, pay attention to the primer cup and the lip that mates up to the underside of the shell plate. Clean the underside of the shellplate where the cup mates up to it and the slots that hold the cases then tighten it all back up. I have to snug up the shellplate bolt several times during a reloading session as it tends to loosen a bit.

Also clean the primer punch surface inside the cup (where the primer sits) since debris builds up there.

Make sure nothing is keeping the ram from bottoming out since the SDB primes on the down stroke it could be possible to have issues if it is not achieving full travel. If you are hitting the stop nub I would assume it's G2G.

 

[Bahamadon]

Check this measurement. Should be 1.410 with no compression of primer cup.

 

[jimmyjames8]

From Dillon website: "

• Remove the primer slide from the primer feed.
• Using calipers, measure from the underside of the primer slide to the top of the cup. It should be 1.410", plus or minus .003".
• If necessary, use a clamp or vise to reseat the primer cup and punch, and hold them down in place while you tighten the setscrew."
• 
  
• The SDB is not Dillon's finest hour. I had one for a number of years and I had 4 caliber set ups. I had lots of problems with consistent seating depth/COL trying to load match grade 38Super. Finally threw in the towel, sold it and bought a 650. Had lots of problems with that 650 as well. Primer system.

Ive never loaded 9mm that was factory crimped primers that I know of but anything else with a crimpred primer requires reaming or swaging the crimp out.

 

[Catfish]

I actually do have a lot of trouble getting it to touch the stop nub on the primer seat stroke. Thanks for the info Ill let ya know what i find.

 

[Catfish]

Ok i cleaned the priming mechanism and inside the press. The primer cup is in spec at 1.411”
The shell plate had loosened a bit, tightened it.
Ran a test batch of 10 rounds making sure the handle touched the stop nub... NVM that. ETA shining a light on it, I cannot make the handle touch down while seating a primer. Hmmmm.

2 out of 10 were flush and 1 was proud.

Looking at the linkage nothing is cracked but the side links have a lot of play in them. Maybe something not right there?

 

[Clicker]

Sounds like it's time for new link arm bearings which are easy to replace.

I noticed a big improvement in overall feel after replacing the wave bearings for the ram but it's a more involved process. But if ya got the link arms removed you might consider replacing them also although I don't think they affect the priming operation.