dahermit
dahermit
20 posts
Joined October 2007

Large primers not seating deep enough.

I have recently switched from the small primer system to the large system. Small primers were seating fine.
No matter how much force is used, the large primers remain slightly proud of flush (about .002).
My Dillon 550b is more than 20 years old with tens of thousands of rounds loaded on it, both large and small primers.
The brass being used are Winchester and W-W, with none having crimps.
Primers are Winchester Large Pistol. It is NOT the primers.
There were purchased as "once fired" and this is their second loading on my Dillon 550b...the Winchester primers seated fine last time.
I disassembled the press about twenty years ago and converted all the oil holes to grease fittings and have kept it greased since.
At reassembly, the Main Shaft was rotated 180 degrees (to compensate for possible wear) and reassembled. Therefore, the Shell Plate Bolt Set Screw is now on the right side of the shaft, not the left.
The Main Shaft has be lubricated periodically with Mobile 5W-20 full synthetic oil.


What I have already tried and observed:
The Shell Plate is appropriately tight...screwed down all the way, backed off to just allow plate to turn.
The Cartridge Spring (13926) is not riding the casings.
The Roller Bracket Shell Platform (14280) screws are not loose or backed out, contacting the primer slide.
The Primer Cup is adjusted using a spent primer and a small vise to set the depth.
I swapped-out (and reset using a spent primer), The Primer Seating Cup Spring, the Cup and the Primer Seating Punch (from my spare parts kit), to no avail.
The Primer Track Bearing (14015) shows wear on the rear (opposite the primer seating punch), but does not seem to be worn enough to be causing the problem.
The link Arm, Right w/Hook (13747) demonstrates lateral play as does Crank (13409).
There are no cracks observed in the bottom of the bottom of the Frame (20094) where the Main Shaft exits.
jforwel
jforwel
52 posts
Joined November 2007

RE: Large primers not seating deep enough.

The same thing happened to me, and I noticed that the handle had some spring to it when I pushed back to seat a primer. Further inspection revealed cracks in the crank of my 30 year old 550B. Dillon replaced the crank with some upgraded parts and it is like new again.
rmoser38
rmoser38
44 posts
Joined October 2008

RE: Large primers not seating deep enough.

Another thing to check is to look and see if the wing nut on the powder return is to tight. If it is screwed in to much it will not let the platform lower enough to fully seat the primer. When pushing forward on the handle to seat a primer the spring on the powder return should be about 3/4 compressed. When I push the handle on my 550 all the way forward to seat a primer the seating punch will be above the platform by a good bit.
dahermit
dahermit
20 posts
Joined October 2007

RE: Large primers not seating deep enough.

I checked the powder rod...it is not interfering with primer seating.
I also find that by pushing the handle all the way forward without a casing in the station, that the primer seating punch seems to clear the shell plate.
Also, when I try a case with the spent primer removed and pocket empty, I find that the seating punch will enter the primer pocket deep enough to stick. (as per Dillon's instructions as to confirming that the primer punch is rising high enough.) However, a live primer will not seat any deeper than "almost" flush, and then it requires excessive force...so it is not a matter of "pushing harder."
It is interesting that doing an internet search, primers not seating deep enough with a 550b seems to be somewhat of a common ailment and as of yet, no one seems to have a definitive answer as to how to overcome it.
I have a supply of ammo (other than W-W, Winchester .45 ACP), mostly small Federal primers, that I have previously loaded on my 550b and thought them to be seated correctly, however, checking them they too are just flush or about .001 from flush, many different headstamps, .38 Spl., and .38 Super., so the problem is not with just large pistol primers in W-W, or Winchester brass.
I think I remember someone suggesting shimming the bottom of the hole in which the primer seating punch sits with shims made from cheap feeler gauges. I cannot remember if they said they actually did it and it did not work, or if it was just a suggestion. I tried that awhile back and it did not seem to seat the primers any deeper.
I have cut two more .003 shims (using a leather punch and cheap feeler gauges), and will add them to the bottom of the hole and see if that additional .006 will help...but I am getting pretty discouraged. One guy posted that he solved the problem with his 550b by buying a Dillon 1050.
dahermit
dahermit
20 posts
Joined October 2007

RE: Large primers not seating deep enough.

The two .003 shims were minimally effective. Primers still slightly proud of flush in the primer pockets unless excessive force is used to seat them. If additional shims are added (in effect making the punch longer), the primers tend to catch on the shell plate when rotated, so shimming the priming punch does not seem to be the answer.

Examining the primer seating system (punch length, cup, and spring), it is the spring that seems to be the "stop", when the handle is pushed all the way forward when seating a primer in that the cup does not make contact with primer slide. The coils appear to "collapse" and contact one another and limit travel. I have swapped out the spring from my spare parts and that did not fix the problem...the spring(s) were the same height.

My primer slide with punch are within specs (1.218) as is the length of the primer punch (1.001).

In short, there seems to be a critical balance between the dimensions of the Shell Platform, Shell Plate, the Primer Punch, Spring, and thickness of the Primer Slide. In other words, there seems to be a design limitation that does not allow any adjustment.

If anyone has a remedy for the problem of non-flush primers and the Dillon 550b, I am all ears. I am not happy to have to re-seat primers to the bottom of the primer pockets using my old Lee hand-held priming device...I got a Dillon for its supposed higher production rate.
rmoser38
rmoser38
44 posts
Joined October 2008

RE: Large primers not seating deep enough.

If the primer punch is going into the brass and sticking when you don't have a primer on it, then the press is not the problem. If it is stopping short with a primer than I would think it is the primer and not the press. Look closely at the primers and see if the anvil is sticking out. Have you tried a different lot number of primers or any other brand of primers? Or as another poster suggested check the crank and pivot arms for cracks when pushing forward, which would limit the amount of force applied to the primer when seating. But would not be present when just pushing the primer punch up with no primer.
dahermit
dahermit
20 posts
Joined October 2007

RE: Large primers not seating deep enough.

"If the primer punch is going into the brass and sticking when you don't have a primer on it, then the press is not the problem."

I have measured large pistol primers and they are .210 in diameter. I have measured my Dillon 550b primer punch and it also reads .210, so when one gets the punch stuck in an empty primer pocket it is a red herring. During the priming operation, the punch, being the same diameter as the primer it is attempting to seat, acts as a stop instead of the primer bottoming out in the pocket.

I took off .0015 from the primer punch at the leading edge, now the punch (slightly smaller than the primer) does not stick in an empty pocket, but the primers are still high...something is still acting as a "stop" and not letting the primer bottom-out.

As for you other questions, it is evident that you did not read the original post or the subsequent posts...I have already responded to those issues.
rmoser38
rmoser38
44 posts
Joined October 2008

RE: Large primers not seating deep enough.

The primer punch is supposed to get stuck in the brass when there is no primer. It is a way to let you know that you are either out of primers or the primer was not dropped into the primer punch. When seated a primer will be only very slightly below the level of brass so the punch never enters the brass when a primer is present. If the primer is not flush the punch never contacts the brass. I suggest you call Dillon Support when you can be in front of your press and they can take you through a check of the whole primer feed system to find the problem.
dahermit
dahermit
20 posts
Joined October 2007

RE: Large primers not seating deep enough.

In my perusal of a google search on "550b high primers" I can across an old thread in the Brian Enos forum. The guy posted a link to where Brian Enos suggested your technique of pulling the press forward with one hand while pushing the handle forward to seat the primer (the link was broken, but I understood what he was talking about). I have tried that system, and it seems to be working. Evidently it keeps the press, and perhaps the strong mount from flexing when seating the primer. My "strong mount" is not a dillon product. It is a self-made, welded, using hot rolled steel of slightly larger thickness than the dillon product. It is about two inches taller than the commercial strong mount inasmuch as I did not have the dimensions to go by, only pictures), which may or may not have contributed to the flexing during the priming operation despite the heavier steel used in mine. At this point, I am not going to deem the problem solved, inasmuch as I want to load about 100 .45 ACP cartridges so I am sure I am not chasing a red herring.