"If it ain't broke, don't ..." -- a sorry tale of woe and some lessons learned

[Nostrum Damus SASS #110702]

I'm pretty good in my shop and at my reloading bench with getting stuff right, making wrong stuff right again, general MacGyver'ing, and the like.  So when a pard started having trouble seating primers on his Dillon XL750 after having had no trouble for the first, oh let's say, 7K rounds, I of course jumped at the chance to diagnose and fix it.  Now, I've done a lot of "upgrading" to my own 750 and I know the machine pretty much inside-out.  Nonetheless, nothing I saw on his machine jumped out at me as being broke, incorrectly set up or calibrated, or anything else.  Yet primers would not seat consistently sub-flush; in fact, the reject rate was as high as 70-80% in some batches we tried after disassembling and reassembling this or that.  I asked all the right questions: did something happen that you can recall when this problem started (no); have you switched any of your components (no); does anything feel different (no); etc etc etc.  

One thing seemed particularly odd to me -- the amount of force required to seat a primer ranged from "normal" (rare) to unusual (often) to extraordinary (occasionally).  Primers would nearly always be tilted in the case base, with one side of the cup's base protruding above flush.  But it was not uniform from round to round.  I was stumped.  After ruling out everything I could think of, I learned that once in a blue moon, truly rarely, someone has exercised their 750 with such force that one of the elements of the linkage connected to the crank that raises and lowers the ram got bent; in one extreme case I found, the crank casting was even cracked.  So, finally and completely exasperated, we concluded that one of the linkage elements was bent but that we did not have the tools or equipment or parts to deal with it.  So, after some phone calls, the press was boxed up and shipped back to Dillon for diagnosis and repair, along with a small pile of the components that we were unable to successfully assemble into working cartridges.

And here's where the lessons started to be learned.

After a few days with the machine, my buddy was contacted by Dillon.  "There's nothing wrong with the press," or words to that effect.  The next words shocked me: "All of your brass is defective."  They explained that the flash hole surface of every primer cup looked like a volcano protruding downwardly towards the base of the case.  When my pal told me this, skyrockets screamed and exploded inside my head.  I felt pretty stupid, and immediately understood what the problem was, and how trivial it was to fix it.

When I asked if something happened that he could recall when this problem started, he said no, and I'm sure he actually didn't remember.  But now I asked the more specific question: did you break off a decapping pin in the decapping die in your decapping toolhead?  "Yes."  Like me, he has a dedicated decapping toolhead for high-speed decapping of spent brass by running it, with no other dies, through the press.  I said "go look at your decapping die and you'll see that you've set the entire pin too low -- you've pushed the wider shank that holds the actual pin down so far in the die that the transition shoulder from the pin to the shank has crushed and caved in -- and thus pushed outwardly in volcano shape -- the flat flash hole surface of every piece of brass you've decapped since that time."  A minute later, he came back and said "you're right."

Shame on me for not even considering the possibility that the problem was not with his loading process, or the Dillon machine itself, but was instead with his decapping process and the improperly set decapping pin in the decapping die in the dedicated decapping toolhead -- which was never on the machine when I was inspecting and working on it, so I never saw it.  Shame on me for not closely inspecting any of his brass.  It just did not occur to me that EVERY case could be damaged in such a way to prevent proper seating of a primer.

The never-broken XL750 is back at my pard's bench, though it will be a few more days before it is up and running again as a primer feed assembly mounting bolt got bent in transit and a new assembly is on its way from Dillon's service folks.

What became of all of the damaged brass, you wonder?  While it might be tempting to try to repair it with expensive specialized tools that will re-form the primer cup to, or close to, original specifications, we agreed that the much better course of action was to give the lot of it to the brass recycler in exchange for lead (we get 1:1 swap).  

End of story.

[Griff]

I gotta ask a question here... Why on earth would one decap separately from simply loading from decap to finished shell.  It simply adds an extra step sitting each cartridge at the decap station and a pull of the handle.  So instead of 5 pulls to cycle a piece of brass you've made it 6.  And if you're using a case feeder, an extra loading on that piece of equipment.  I get it if you're wet tumbling, but I can decap mine by hand and take the opportunity to inspect (maybe only a cursory inspect) each piece as it comes out of my range bag and goes to the "to-be-tumbled" bucket with a short visit to my hand operated decapper in between.  Meanwhile I can be enjoying my favorite U-Tube channels or a TV program.  I've only been reloading for 54 years, and will enjoy learning something new.  

 

The RCBS Brass Boss makes quick labor free corrections to uniform your brass, especially primer pockets and flash holes.  

[Leroy Luck]

8 minutes ago, Griff said:

Why on earth would one decap separately from simply loading from decap to finished shell

I do the same process and here’s why. I get several primers that don’t come all the way out of the pocket and then end up reseating in the priming station. I’m using a 650 instead of a 750. The only cause I can figure is the primer sticking to the decapping pin and not falling into the spent primer catch. I have modified the point of the pin and think I have less issues, but don’t really know. 

It does help that I do wet tumble, but I don’t want primers causing me issues during the loading process. 

 

[The Original Lumpy Gritz]

5 hours ago, Leroy Luck said:

I do the same process and here’s why. I get several primers that don’t come all the way out of the pocket and then end up reseating in the priming station. I’m using a 650 instead of a 750. The only cause I can figure is the primer sticking to the decapping pin and not falling into the spent primer catch. I have modified the point of the pin and think I have less issues, but don’t really know. 

It does help that I do wet tumble, but I don’t want primers causing me issues during the loading process. 

 

Get a longer pin and round the tip.

[Eyesa Horg]

I now deprime before tumbling as it does eliminate the hiccup of a spent primer being pulled back into the pocket.

[Gateway Kid SASS# 70038 Life]

4 hours ago, The Original Lumpy Gritz said:

Get a longer pin and round the tip.

Or simply use the correct decapping pin and extend it down perhaps an extra 5 or six thousandths. 
Also why not use the machine as designed? Seems like extra work for diminishing returns. I have 15+ year old brass that the primer pockets have gotten loose after 25 or 30 reload cycles, (you can feel them) and I simply set them aside, recover the primer and recycle the brass, but have never actually cleaned the pockets for CAS ammo. 
Guessing original idea was to clean primer pockets with wet tumbling, for precise hunting purposes or really long range where extra effort to uniform the brass makes sense, but again for CAS at no more than 15 yards, any increase in accuracy from perfectly clean primer pockets would be marginal at best. 
YMMV
Regards

    

Gateway Kid

[Nostrum Damus SASS #110702]

As you said you can understand, we deprime before wet tumbling.  You'd probably be amazed at how little time it takes to deprime 1000 cases in a 750 with a case feeder and dedicated depriming toolhead.   

[Eyesa Horg]

I currently use a single stage reloader and do it when we get home from a match. Gives me a chance for a quick brass check and takes minimal time to deprime both of our cases. Guessing less than half an hour.

[Gateway Kid SASS# 70038 Life]

10 hours ago, Nostrum Damus SASS #110702 said:

As you said you can understand, we deprime before wet tumbling.  You'd probably be amazed at how little time it takes to deprime 1000 cases in a 750 with a case feeder and dedicated depriming toolhead.   

Oh I am well aware of how long depriming takes for 1000 rounds, in the scheme of things not particularly long. 
but

1000 extra mind numbingly boring pulls on a handle (which will most likely be repeated when you complete your reloading later) seems like a bit more work than my elbow needs to be faced with. Besides those same 1000 handle pulls would have me done with 1000 completed rounds that work just fine, and then moving on to something else. 
Just like skinning cats there are hundreds if not more ways to do things, and if your process makes you (and others) happy, go for it. 
Regards

    

Gateway Kid

[Nostrum Damus SASS #110702]

51 minutes ago, Gateway Kid SASS# 70038 Life said:

Oh I am well aware of how long depriming takes for 1000 rounds, in the scheme of things not particularly long. 
but

1000 extra mind numbingly boring pulls on a handle (which will most likely be repeated when you complete your reloading later) seems like a bit more work than my elbow needs to be faced with. Besides those same 1000 handle pulls would have me done with 1000 completed rounds that work just fine, and then moving on to something else. 
Just like skinning cats there are hundreds if not more ways to do things, and if your process makes you (and others) happy, go for it. 
Regards

    

Gateway Kid

It is not the same 1000 pulls twice.  When the only die in the toolhead is a Lee Universal Decapper in station 1, there is virtually no resistance whatsoever in either direction of handle travel. The press arm actually sort of bounces between fully up and fully down, with almost no effort at all. You literally raise and lower the handle as fast as you can manage to do it. I'd encourage anyone to give it a try before deciding whether to do it or not.  As they say, unless you've actually tried it, you don't know what you don't know.

[Shawnee Hills]

While I am rarely a fan or owner of Lee Precision products, I have the APP set up as a dedicated decapping only station.  While cheaply made, it does work well for this task.  It is fast and keeps the Dillon free for loading.

[Matthew Duncan]

On 7/19/2026 at 11:38 AM, Nostrum Damus SASS #110702 said:

…When I asked if something happened that he could recall when this problem started, he said no, and I'm sure he actually didn't remember. 

With 27 years in the service business I’ve learned that 95% to 99% of what the customer tells you is wrong.

[Cheyenne Ranger, 48747L]

More on the story--I, being the guy that ended up with the brass, and tried to "fix/deepen" the primer pockets back to their original depth.  So far no joy,

Took

took a drill bit of proper size and flattened the bottom, it was slightly rounded.  Then put it in a drill press backwards and measured how deep a 'good' primer pocket was (case on table, primer pocket up). Put a damaged case in and attempted to push it down to the right size--crumpled the case before I could get the pocket deepened.  

 

After repeated attempts, still had primers proud of the case

 

cr;,

[Nostrum Damus SASS #110702]

8 hours ago, Cheyenne Ranger, 48747L said:

.....

 

After repeated attempts, still had primers proud of the case

 

cr;,

recycle recyle recycle

[Cheyenne Ranger, 48747L]

10 hours ago, Nostrum Damus SASS #110702 said:

recycle recyle recycle

 

yes, that's where they are headed.  We can get , so they won't totally go to waste

[Snakebite]

Very interesting. I bought a new 750. Had nothing but trouble with it from day one. The first couple of thousand rounds would have a high number of primers seated crooked or sidewise. As time passed, the problem got worse. Two weeks ago I had 50 rounds out of 500 that were bad. I tried to contact Dillion, but ended up filling out a form on line that said they would contact me withint 3 days..... well, that didn't happen. I took off the primer and the shell plate. I applied a thin layer of silicone grease to everything and put it all back. Yesterday I loaded 700 rounds, and not one of them had a tilted primer.  Maybe the sell plate wast just too tight from the factory... don't know... I just know that it is now working. 

[Nostrum Damus SASS #110702]

6 hours ago, Snakebite said:

I took off the primer and the shell plate.

What do you mean by "took off the primer"?  The priming assembly?  And by "shell plate" I assume you mean the caliber-specific rotating plate?  You always need to adjust the shell plate mounting bolt to achieve the right amount of downward force on the plate so that it rotates freely but does not wobble.  There should be as little vertical play as possible while still permitting unrestrained rotation.  I don't think that Dillon intends for the user to start using the press without going through the initial set-up steps, including properly adjusting the shell plate mounting bolt.  Did you do that?  It sounds like your mounting bolt was too tightly cranked down, which was preventing the shell plate from completing its rotation to the proper point where the shell case is perfectly aligned with the primer cup.  That tiny misalignment will cause tilted and crushed primers every time because the upper edge of the primer catches on the interfering or overlapped base of the case on its upward travel and tilts over on its side before being rammed into the primer pocket at an angle or even completely sideways.

Another solution is to buy and install a thrust washer between the head of the shell plate mounting bolt and the shell plate, such as the one sold by Unique-Tek in the kit of excellent upgrade parts at https://uniquetek.com/shop/ols/products/xl-750-ultimate-bearing-kit

In my experience I have only VERY rarely found (or even heard) that a reloading issue was actually caused by the XL750 press.  In virtually every instance, the problem is user error, mine included, always.  The hard part is figuring out what we're doing wrong, but this forum is jammed with tons of reloaders who have tons of experience with every press and accessory you can name, and many you can't name.  When you are having a problem, just ask here and I'll wager that you'll get your answer in a couple of hours if not faster.

[Snakebite]

Yes, the priming assembly and shell plate. I've had many Dillion loading presses in the past 40 years. I've been loading for well over 60 years. All of the loaders that I have had in the past came totally setup and fully tuned and adjusted for the Caliber that you ordered. I just assumed that this 750 was the same, so I certainly did not go about changeing what IMO should have been a factory tuned loader. O-well, things change. It's working fine now.

 

Snakebite

[Nostrum Damus SASS #110702]

Glad to read all's well now. Never trust someone else's work! It's just like re-tying the knots on the fishing rod just handed to you by your guide. Maybe his knots were great when he tied them but how long ago and how many hard pulls have there been since then, and how much UV has the knot been exposed to? All unknown and unanswerable questions. Just DIY -- at least you know exactly who to blame when the knot fails!!

[Sheriff Dill]

17 hours ago, Snakebite said:

Very interesting. I bought a new 750. Had nothing but trouble with it from day one. The first couple of thousand rounds would have a high number of primers seated crooked or sidewise. As time passed, the problem got worse. Two weeks ago I had 50 rounds out of 500 that were bad. I tried to contact Dillion, but ended up filling out a form on line that said they would contact me withint 3 days..... well, that didn't happen. I took off the primer and the shell plate. I applied a thin layer of silicone grease to everything and put it all back. Yesterday I loaded 700 rounds, and not one of them had a tilted primer.  Maybe the sell plate wast just too tight from the factory... don't know... I just know that it is now working. 

I had the same problem when I was learning(still learning 😁) to reload on my 650. Every 50-100 rounds at least on primer would have been put in sideways. My issue was the shell plate to tight and not allowing everything to advance correctly. 
 

I just ran into a primer issue recently with a bag of brass I bought were some of the brass is military brass and the entire spent primer will not come out not allowing the new primer to go in. Luckily you can feel it in the handle and can save the new primer and toss the brass in the scrap bucket. 

[Nostrum Damus SASS #110702]

Most military brass is Berdan, not Boxer, primed and is not ordinarily reloadable on the same equipment as that used to reload Boxer primed brass due to the integral anvil in the Berdan style primer pocket

[Rye Miles #13621]

I have never deprimed before tumbling the brass and I’ve never had a problem in 20 years of reloading. I’ve reloaded. 38 (which I’m shooting now) .45 Colt, .45 acp, .44-40 . Never deprimed. 
I also don’t do the wet tumbling I use corn cob and Dillion case cleaner.

[Sheriff Dill]

4 hours ago, Nostrum Damus SASS #110702 said:

Most military brass is Berdan, not Boxer, primed and is not ordinarily reloadable on the same equipment as that used to reload Boxer primed brass due to the integral anvil in the Berdan style primer pocket

The brass I ran into is PCM brass. 

[The Original Lumpy Gritz]

3 hours ago, Sheriff Dill said:

The brass I ran into is PCM brass. 

Do you mean  PMC? 🤔

[Sheriff Dill]

2 hours ago, The Original Lumpy Gritz said:

Do you mean  PMC? 🤔

Yes thats the headstamp just checked it. Thanks for the correction. Was frustrated with them and tossed them immediately in the scrap bucket. 

Edited July 25 by Sheriff Dill

[Gateway Kid SASS# 70038 Life]

PMC is typically okay to reload. While not the greatest it is readily available and gets mixed into lots of range brass. I have reloaded literally thousands of rounds of PMC in various calibers with no problems. Russian stuff like Tula and Wolf is pretty much all Berdan primers and unless you have some specific (and expensive) equipment, for all intents and purposes is not reloadable. Also much of the Russian ammo can be steel case not brass which brings its own problems to reloading. I use military in both .223 and 7.62x51 for my AR’s and while it has always been crimped in primers, it has also all been Boxer primed, thus reloadable. Generally swaging after resize/deprime will take care of the military style crimp permanently. Best of luck. 

Edited July 25 by Gateway Kid SASS# 70038 Life

[Sheriff Dill]

1 hour ago, Gateway Kid SASS# 70038 Life said:

PMC is typically okay to reload. While not the greatest it is readily available and gets mixed into lots of range brass. I have reloaded literally thousands of rounds of PMC in various calibers with no problems. Russian stuff like Tula and Wolf is pretty much all Berdan primers and unless you have some specific (and expensive) equipment, for all intents and purposes is not reloadable. Also much of the Russian ammo can be steel case not brass which brings its own problems to reloading. I use military in both .223 and 7.62x51 for my AR’s and while it has always been crimped in primers, it has also all been Boxer primed, thus reloadable. Generally swaging after resize/deprime will take care of the military style crimp permanently. Best of luck. 

Some of it I found worked no problem. I only found it when I was checking for high primers and case gauging them. 

[The Original Lumpy Gritz]

Never had any issue with PMC.

Have used these reloads in select fire weapons and never had any problems. 

[Nostrum Damus SASS #110702]

Interesting.  According to the interweb, PMC has never manufactured Berdan-primed ammunition, although they did make and sell Berdan primers for reloaders at some point in the past.

[Eyesa Horg]

1 hour ago, Nostrum Damus SASS #110702 said:

Interesting.  According to the interweb, PMC has never manufactured Berdan-primed ammunition, although they did make and sell Berdan primers for reloaders at some point in the past.

I think Dill's were just crimped like military rounds.

[Nostrum Damus SASS #110702]

Just to put a ribbon and tie a bow on the original post, said pard's 750 is up and running, purring right along like it should, cranking out perfect rounds except when a piece of damaged brass shows up, which results in a reject, a de-prime, and another case tossed into the recycle pile.

Edited August 4 by Nostrum Damus SASS #110702

[Nostrum Damus SASS #110702]

To perfectly illustrate what happened, this is what a Dillon Pro Series decapping pin looks like:

Notice the conical transition portion I've circled in red.  And this is what happens when you set your Dillon Pro Series decapping pin too low, thereby forcing that conical transition portion through the flash hole:

 

Notice that the flash hole has been opened up.  What you might not be able to see is that the rim of the now-volcano-shaped wall of the primer pocket extends into the space normally occupied by a fully seated primer.  That mechanical interference prevents complete seating of the primer, no matter how hard you push the operating handle of your press.

 

Edited August 5 by Nostrum Damus SASS #110702

[Nostrum Damus SASS #110702]

So, how do you know how low is "too low" to set the decapping pin?  Different pins have different profiles, some with conical transition portions, others with flatter or even right-angle transition portions.  Here's what you can do, starting with NO DIE in the decapping position.

1. Put a known good case in station 1 of your progressive press (or in the shell holder of your single stage press).

2. Raise the case fully.

3. Install the sizing/decapping die or whatever you are using to decap (such as a Lee Universal Decapping Die) WITHOUT THE DECAPPING PIN INSTALLED.  This means screwing down the die until it meets the shell plate/holder.

4. NOW install the decapping pin into the die with the collet opened sufficiently so that the pin is free to move up and down easily.  See where the pin body/holder sits when it is actually resting on the inside of the primer pocket, with the actual pin extending through the flash hole.

5. Then set the pin a sufficient vertical distance higher than its resting position, depending on the length of the actual thin portion of the pin you happen to be using, and tighten the collet as you would always normally do.  I set mine about .100" above the resting point to account for variations in primer cup wall thickness between manufacturers (my regular cowboy mixed brass has more than 20 different headstamps). 

 

This procedure ensures that you won't damage the flash hole during the decapping operation.