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.