Primer Seating Causes Firing

[alamogunr]

Was loading .45ACP on the Dillon 550 yesterday. I had completed about 130 rounds when a primer went off when seating. After checking to be sure I hadn't embarrassed myself, I checked the case in station 1. I expected to find 2 primers, one in the case and one in the primer cup. There was only the primer(fired) in the casing. The primers I was using were Wolf large pistol. I'm trying to get rid of all Wolf primers. I've had too many problems with Wolf small pistol primers and won't use them at all. Up to now I haven't had any problems with large primers.

I can't figure out what I did that might have caused the primer to go off. Has anyone else had this happen? I'm not trying to find an excuse, just what may have happened so it doesn't happen again.

[BigAlofPa.]

Sometimes i get powder in the priming ram cup. Maybe that is what happened to you. I use CCI primers. I think they have a harder metal in them.

[trebor44]

Started reloading with a single stage, used a hand primer never has an issue. Years ago added a Dillon, loaded a lot of rounds, used many different brands of primers. But had a primer go off when seating on the Dillon. I think it was a Wolf primer. Kind of a wake up call!

[ioon44]

I have had that happen one time on my 550 since 1986 and well over 250,000 loads, I just called it a bad primer.

[XDROB]

But what is triggering them? I have a Hornady LnL and the primer (inserter?) driver is flat and covers the whole primer. I do use Wolf and not had a problem.

Sent from my SM-N975U using Tapatalk

[bedbugbilly]

I don't reload 45 ACP nor use a Dillon, etc. - but could you tell from the primer that wen to ff if there was an indentation on it or was it too messed up to tell? I'm wondering if a piece of something - dirt, metal, etc might have gotten between the flat face of the primer driver and the primer?

Like I said, I have no experience with the Dillon or similar as I load on a single stage or a 4 hole Lee turret - but - I finally got a tumbler about a year ago and now tumble my brass in SS. I'm very careful about rinsing the cases, drying, checking them 0 just to make sure I have all of the SS pins - and I use a strong magnet to collect them. I had cleaned some range pick-up .223 classes a year ago - I deprive with a universal de-priming die before tumbling. I inspect my cases before I put them in the FL Lee die that I use to FL resize them and was using the depriving pin of the die to size the mouth on the way out. I looked inside the case - it looked good but when I ran it up into the die I felt a "crunch" and immediately backed out. Upon closer inspection, I found what looked like to be a tiny piece of SS pin that evidently had stuck somehow on the inside - I didn't damage the die or die pin, but did toss the casing. the pies was small enough that it cold have got through the priming hole if everything had been just right. So moral is . . . things do happen.

I have often wondered - since 45 ACP brass comes in both small and large primer - as careful as a person may be - if loading range brass - what happens on a press such as a Dillon where you are automatically priming in the cycle and are using large primer brass but a small primer casing somehow gets mixed in? Is that enough to set a primer off or does it just crush it?

[Nueces]

I would consider the possibility that something was hoboing in the primer pocket and caused the anvil to compress the pellet during seating. Carefully deprime that case and look for something like a granule of tumbling media, though it could easily have been shot through the flashhole.

[Tatume]

A primer can fire if compressed excessively. Was this a military case? If so, then I would suspect a primer pocket crimp to be the culprit.

[alamogunr]

I don't reload 45 ACP nor use a Dillon, etc. - but could you tell from the primer that wen to ff if there was an indentation on it or was it too messed up to tell? I'm wondering if a piece of something - dirt, metal, etc might have gotten between the flat face of the primer driver and the primer?

Like I said, I have no experience with the Dillon or similar as I load on a single stage or a 4 hole Lee turret - but - I finally got a tumbler about a year ago and now tumble my brass in SS. I'm very careful about rinsing the cases, drying, checking them 0 just to make sure I have all of the SS pins - and I use a strong magnet to collect them. I had cleaned some range pick-up .223 classes a year ago - I deprive with a universal de-priming die before tumbling. I inspect my cases before I put them in the FL Lee die that I use to FL resize them and was using the depriving pin of the die to size the mouth on the way out. I looked inside the case - it looked good but when I ran it up into the die I felt a "crunch" and immediately backed out. Upon closer inspection, I found what looked like to be a tiny piece of SS pin that evidently had stuck somehow on the inside - I didn't damage the die or die pin, but did toss the casing. the pies was small enough that it cold have got through the priming hole if everything had been just right. So moral is . . . things do happen.

I have often wondered - since 45 ACP brass comes in both small and large primer - as careful as a person may be - if loading range brass - what happens on a press such as a Dillon where you are automatically priming in the cycle and are using large primer brass but a small primer casing somehow gets mixed in? Is that enough to set a primer off or does it just crush it?

The primer that fired had an imprint of what looked like the point of the anvil pushed out. The anvil seemed to be set further into the cup than normal. Don't know if that happened when it fired or not.

I have a wet tumbler but have not used it on these cases. Also, I have been accumulating small primer brass and am well aware of problems of mixing sizes. There was no small primer anywhere around my bench and I have been looking at each case before I inserted it into the first station.

All I could think of was that the primer had the anvil seated deeper than it should have been and the punch pressure was concentrated at the point of the anvil.

As for foreign matter in the pocket, I deprimed the casing immediately and didn't notice anything. Too late now to look for anything like that.

This could have been military brass. The headstamp says TZZ 85

[Tatume]

This could have been military brass. The headstamp says TZZ 85

Yes, that is a military head stamp, Israeli Military Industries, Tel Aviv, Israel. As I said, I suspect a crimped primer pocket caused the incident.

[alamogunr]

That seems to be the most likely cause. I didn't notice any extra effort required to seat the primer but I could have completely missed it when the darn thing went off.

I think I've got some IMI brass in 7.62mm but it is stamped IMI.

I've noticed that occasionally one of my "once fired" brass primes easier. I just chalked it up to a many fired piece.

[onelight]

I have often wondered - since 45 ACP brass comes in both small and large primer - as careful as a person may be - if loading range brass - what happens on a press such as a Dillon where you are automatically priming in the cycle and are using large primer brass but a small primer casing somehow gets mixed in? Is that enough to set a primer off or does it just crush it?
I have had a small primer case get into my large primer cases several times on Lee progressives the ABLP you get good feed back and can easily feel the problem before any damage is done and remove the case.
I have loaded on a 550 Dillon but not 45 acp.

[dverna]

Good reminder to ALWAYS wear eye protection when priming with any tool.

[Tatume]

My supply of 45 ACP cases is such that I no longer feel compelled to use military cases. I just throw them into a bucket because I'm too frugal (dumb) to throw them out (which I should).

[alamogunr]

Good reminder to ALWAYS wear eye protection when priming with any tool.

AMEN! And I do. Also when casting.

[MT Chambers]

The next step in the process is depriming.

[Conditor22]

I think that somehow, something hard and large enough to dent the primer got on the priming ram and set it off.
The lee loadmaster comes with a primer blast shield (that I've never seen anyone use).

YES ALWAYS wear glasses/safety glasses when doing anything with guns. It's a good habit. you only have 2 eyes and they don't grow back.

My 2¢

[wv109323]

I agree something got on top of the primer ram and set the primer off. I use Win. Primers and many times powder residue indents the primer. I have not had a primer go off but get indented primers.

[M-Tecs]

Primers normally don't denotate with a slow compression. I have tested this several times by squeezing them flat in a machine vise. My guess is the crimp held the primer until enough pressure was applied and it popped in with sufficient force and velocity to denotate.

I gave a buddy a bunch of GI brass that he did a poor job removing the crimp. He only uses a hand seater but he managed to set a 7 or 8 off before he called me. After he properly removed the crimp he has had zero issues.

[Tatume]

I was very surprised when a primer detonated upon being run over by a hard rubber wheel on a dolly. I don't know if I could ever reproduce the event, but it happened at least once.

[Rich/WIS]

Don't use a progressive but had two Win LP go off when priming on the upstroke with my old Lyman Spartan.

[JoeJames]

I use either Winchester or CCI primers, and a very old Lee Auto Prime. I noticed in the fairly recent Lee Manual that they recommend limiting the number of Winchester primers in the tray depending on whether they are large or small primers, and flat out discourage the use of Federal Primers in either version of the Auto Prime. CCI's are just fine in any quantity.

[bedbugbilly]

John - thanks for taking the time to answer my questions - I greatly appreciate it. And please realize I was not thinking that you had mixed a small primer case with a larger primer case - I have just always been curious as to the possibility of this happening and the results on a Dillon or similar press.

I'm pretty "low tech" and I prime with a hand primer - I don't reload the quantity that some of you do, especially if you are shooting competition, etc. At one time, I was going to reload 45 ACP as i was going to switch from 9mm to 45 for carry. I got dies, molds, range brass, etc. and then changed my mind and stuck with the 9mm for carry - so I never bought pistol and ended up giving the 45 ACP things to a friend whose Dad wanted to reload 45 ACP. I do relod a number od different pistol cartridges as well as bottleneck rifle cartridges. Mostly, I have always tried to buy 1 X fired range brass as it works fine for what I'm doing.

Not that it has anything to do with what happened to you, but I did learn a lesson on "rage brass" one time. I bought about 3,500 9mm casings from a guy on here - he claimed it was 1 X fired. It was dirt cheap so I got it and figured it would be a good supply to have on hand. It had been tumbled and deprived so that was also a plus - at least in my mind. It was s hodge lodge of bead stamps. I sat down to load a couple hundred and started off hand-priming and talk about a PIA! As I inspected each casing, I tossed some as I don't know what they had been fired in, but the head stamps on some were distorted as if they had been loaded hot or shot in a pistol with headspace issues. I got a good rhythm going on the priming and then - what the heck? I couldn't get the primer started into the pocket. I checked the head stamp - not military - O.K. I'll just toss it. The further I got into the batch, the more issues I had with seating the primer in some of the cases - and it wasn't just one head stamp - it was numerous beadstamps. I was using CCI primers and I have never had an issue with them. I switched to another hand primer I had - same issue -- about every 8th or 9th casing the primer pocket was an issue. At the time, I remember thinking about what would have happened if they were being primed on a automatic press of some type. Long story short - I didn't have a primer pocket swaged at the time and it was such a PIA the I ended up scrapping out all of the casings - it was just too time consuming to fool with. I have never had another issue with 9mm range brass that i he purchased and I never did figure out what the issue was with so many mixed head stamps and difficulty in seating primers - and the same hand primers and batch of CCI primers seated perfectly in other batches oof range brass.

Just glad that you or the press weren't hurt! It may be something that know for sure what caused it. Like already mentioned - a good reminder to all of us to wear safety glasses. An interesting thread and interesting responses - and also a good reminder about checking each casing - I was reminded of that with my own experience with the .223 casing and the fragment of a SS tumbling pin.

[Burnt Fingers]

I sort LPP and SPP 45 brass on my 650. For me it's easy to tell when a SPP gets to the priming stage. I sort crimped 9mm on the other 650, again it's easy for me to tell when one gets to the priming stage.

My buddy for some reason can't tell the difference on 9mm. His solution was to hammer the handle back. I stopped that real quick.

I've had a few sideways primers, but I've never had one go off.

[FLINTNFIRE]

Had one winchester go off in a rcbs hand priming unit , it can and does happen , as to small primer 45acp it is easy to tell when you go to prime on my square deal b , it is one reason I soldered a piece of wire to the shell locator buttons , have run into 9mm and 40 that were not military headstamps that had crimped primer pockets , mixed range brass or once fired can be a crap shoot as to quality and sellers honesty .

[JoeJames]

Cousin gave me several boxes of white box Federal 556 and they all had the crimped primer pockets.

[dannyd]

I have often wondered - since 45 ACP brass comes in both small and large primer - as careful as a person may be - if loading range brass - what happens on a press such as a Dillon where you are automatically priming in the cycle and are using large primer brass but a small primer casing somehow gets mixed in? Is that enough to set a primer off or does it just crush it?[/QUOTE]


Nothing happens; if your loading large primers and get a small primer case you can feel it not going in and stop. If you loading small primers and get a large case same thing you can tell by the feel it as no primer or powder trail after it leaves that station.

[ioon44]

45 ACP brass comes in both small and large primer , when I started dealing with this I developed the habit of looking at the case head before placing it in my 550 shell holder and have found .380 & .38 super when loading 9 mm.

Reloading requires one's full attention.

[cp1969]

I have three ways of priming--Dillon 550B, RCBS Jr., and Lee hand tool. I don't know why but the Dillon does the worst job of the three. It seems like it takes far too much pressure for a compound press and the primers' bases are sometimes noticeably wrinkled. Never had one go off, though.

[jakharath]

I have three ways of priming--Dillon 550B, RCBS Jr., and Lee hand tool. I don't know why but the Dillon does the worst job of the three. It seems like it takes far too much pressure for a compound press and the primers' bases are sometimes noticeably wrinkled. Never had one go off, though.

Howdy, you may need to replace the primer cup and rod on your 550.

[Tatume]

It seems like it takes far too much pressure for a compound press and the primers' bases are sometimes noticeably wrinkled.

I suggest you check the primer slide adjustment. If it is off the misalignment can cause the symptoms you describe. While you're at it, clean the mechanism too. When they are adjusted correctly and clean the Dillon 550 machines do a great job of priming.

[John Boy]

Any primer will ignite if it is struck Hard and Fast. So slow down jerking and hammering the press arm when reloading.

[Tatume]

Any primer will ignite if it is struck Hard and Fast. So slow down jerking and hammering the press arm when reloading.

There is no evidence of this. The OP asked a legitimate question to which he received thoughtful responses, mostly.

[Hossfly]

Never used a 550 but do have a 650 for last 5 years, my mentor instructed me to always limp wrist the priming stroke and if there is too much resistance, stop and pull that one out. Sure nough last week while Running 45’s found about 20 SP in bag of 100 out of 1500 i purchased locally from store getting out of reloading supply business. What a PITA that was, but it avoided the problems i think.

[DougGuy]

I always hand prime, there is just too much adjusting and inconsistencies to prime on the press. If it ain't one thing, it's another that inevitably causes a problem. I don't load 1k rounds at a time anymore so hand priming works for the amount of ammo I need, and if it is hunting ammo, I do everything by hand single stage, weigh each charge, I don't want no surprises when I am aiming at hide.

I only keep WLP for all pistol ammo, and Federal for rifle so that simplifies things and eliminates variables. Variables are what gets you, those are not blatant mistakes, but jusssssssssst enough to make you go Hmmmmmmm when something doesn't go right.

[1hole]

Primers normally don't denotate with a slow compression. I have tested this several times by squeezing them flat in a machine vise.

Ditto. I've slowly crushed primers into a small flat mass in a 70 pound shop vise; I crushed them side to side and top to bottom but with no fireworks. And I've de-capped quite a few live GI pull-downs with Lee's tuff Universal Decapper Die with no events. Been doing this a long time and the only way I've seen a primer go off was from heat or impact.

I have to wonder how vigorously that Dillon's handle was being manipulated. ??

[Tatume]

Ditto. I've slowly crushed primers into a small flat mass in a 70 pound shop vise; I crushed them side to side and top to bottom but with no fireworks. And I've de-capped quite a few live GI pull-downs with Lee's tuff Universal Decapper Die with no events. Been doing this a long time and the only way I've seen a primer go off was from heat or impact. I have to wonder how vigorously that Dillon's handle was being manipulated?


I was very surprised when a primer detonated upon being run over by a hard rubber wheel on a dolly. I don't know if I could ever reproduce the event, but it happened at least once.

Just because you haven't seen it happen does not mean it hasn't happened.

[1hole]

Just because you haven't seen it happen does not mean it hasn't happened.

You are quite correct and neither of us has suggested otherwise.

[cp1969]

Ditto. I've slowly crushed primers into a small flat mass in a 70 pound shop vise; I crushed them side to side and top to bottom but with no fireworks. And I've de-capped quite a few live GI pull-downs with Lee's tuff Universal Decapper Die with no events. Been doing this a long time and the only way I've seen a primer go off was from heat or impact.

I have to wonder how vigorously that Dillon's handle was being manipulated. ??

If that question is directed at me and my Dillon, it was manipulated just vigorously enough to not have a high primer and no more. I even tried adding a step to clean the primer pocket but that didn't make any difference.

[Geezer in NH]

OP having prior problems with Dillon and priming.

http://castboolits.gunloads.com/showthread.php?404172-Adjustment-of-Dillon-550B-Primer-Setup

[1hole]

If that question is directed at me and my Dillon, it was manipulated just vigorously enough to not have a high primer and no more. I even tried adding a step to clean the primer pocket but that didn't make any difference.

CP, my post wasn't "directed" at all, as such, it was just my puzzlement about what might have caused the primer to go off. I doubt that the press being a Dillon had anything directly to do with your event but you did make that mention up front. The "manipulation" question wasn't about how much lever pressure was used, it was about HOW that lever pressure was applied - specifically, was it pressed down slowly or rapidly snapped down??

[Firephoto798]

I recently bought and started using a 550c for 357mag. After loading about 50 rounds I noticed that the rounds were coming out with a small dent in the primers (WSP), like a light firing pin strike. I found debris on the primer seating pin that looked like a compressed chunk of powder. After cleaning it, the dents went away. I now watch the pin closely and occasionally find powder flakes there and clean the pin regularly before it builds up to a larger chunk. I am not sure why I am getting powder flakes there to start with.

[Patrick L]

The one primer detonation I had in my entire 35+ years of reloading was on a shotshell press. A piece of spilled shot rolled into the little hole that the new primer drops into, on top of the seating punch.

[alamogunr]

OP having prior problems with Dillon and priming.

http://castboolits.gunloads.com/showthread.php?404172-Adjustment-of-Dillon-550B-Primer-Setup

I guess I'm convicted.

[abunaitoo]

Must have been scary.
Never had that happen to me.
I've read primers are kind of hard to set off.
I have crushed a few primers seating, but none ever went off.
Knock on wood.
Friend deprimes live primers, and sometimes one will go off.
He's kind of used to it happening.
Said it still makes him jump.
My friend Ed had the primer tube go off.
It made a nice hole in the roof.
He said he almost soiled his pants.
He didn't get hurt.