Primer detonated when seated

magnum12pm

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I was loading some 40 S&W. When I went to seat the pimer it detonated on two casings out of 100. I pulled the casing out and the primer looked as if it was fine. It was seated in the case normally, no dent or any malformation at all. This was on a Dillon 550, never had this happen before, scares the crap out of you. Any ideals how this could happen. They were Federal primers.
 
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I was loading some 40 S&W. When I went to seat the pimer it detonated on two casings out of 100. I pulled the casing out and the primer looked as if it was fine. It was seated in the case normally, no dent or any malformation at all. This was on a Dillon 550, never had this happen before, scares the crap out of you. Any ideals how this could happen. They were Federal primers.
 
Are you sure it's not a Glock priming ram?
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This is pure speculation but, here goes.

Based on my experience, the Federal primers are among the softest. I have noticed that after processing 50 or 100 rounds, my Dillon 550 will begin to pick up some "primer debris" from the de-capping operation. Sometimes the debris will accumulate in the primer ram. I have noticed faint impressions left on the primer by this debris if I am not careful to clear it periodically. Is it possible that debris, like grains of sand, could pierce the rpimer and set it off?

I keep a small artists paint brush next to my 550 and brush the debris away every 10 or 20 rounds.

I hope that helps,

Frank
 
i know primers are hard to come by right now, but if you don't figure out the problem, i would toss them out.
 
Frank's suggestion seems reasonable. I use Win primers, but I have noticed dents in my primers occasionally when there is junk on the Dillon ram. Where you definitely don't want this to happen is with the hand-held variety when you're looking into the casing.
 
Originally posted by keppelj:
Frank's suggestion seems reasonable. I use Win primers, but I have noticed dents in my primers occasionally when there is junk on the Dillon ram. Where you definitely don't want this to happen is with the hand-held variety when you're looking into the casing.


WOW, I hope no one has the case pointed at themselves when their hand priming.

I've had a couple of primers go off when seating them on my Rock Chucker, never had one go off in my Dillon 650.
Clean off your primer punch, and give it another try.

Friend of mine has a 550, and he's never complained about it.

Maybe your pushing too hard when you seat the primer.
If all else fails, do like was suggested above and give Dillon a call, them guy's are good at helping solve problems over the phone.
 
I have loaded 10s of thousands on this Dillion, never had this happen. Never used anything but Federal primers. I watch my primer ram like a hawk because its true its prone to junk accumulating on the ram, do the same as mentioned blow and or brush it off repeatedly. I run about 200 an hour, because I am never in much of a hurry, and tire easily sitting at the bench, so get up move around often. The strange thing to me is the primer looks perfectly seated and no damage of any kind on seated primer, look just like everyone I load and shoot all the time. I had just completely stipped and cleaned the primer assembly like new as I had just finished 1000 38specials, without a hitch. I'm not a newby at this so I am preplexed. The second one that went off didn't scare me, since I was already deaf
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Debris in the primer pocket would be the first thing I'd think of, particularly a chunk of media from the tumbler.

Think of clean primer pockets??

Flash
 
I had a piece of tumbler media get on the primer ram of my 550 the other day. I have a whole box of 9mm that looks like it had light primer strikes. I'm surprised I didn't have a detonation. I'll be paying more attention to the primer ram from now on.
 
As others have mentioned the most likely cause is something on top of the primer ram. Also being too heavy handed with the press is more likely to set a primer off.

When I first started reloading I bought a Lee basic kit where you drove the decapped case into the die using a mallet and then after sitting the primer in the base unit you inserted a rod and drove the case back out of the die and onto the primer to reprime. I did have a primer go off when getting a little excessive with blows to the end of that rod. It launched it about 5' into the air. In over 30 subsequent years of reloading using both single stage and progressive I have not had another one go off.

Primers usually really need a pretty good wack to go off and they need to be dented. I've even crushed them flat and they haven't gone off.
 
Do you still have the suspect case(s)? If so, carefully decap and examine both the primer pocket and the anvil of the primer. Once in a great while, I have encountered an improperly seated anvil and in one case a primer with no anvil at all. Since I use a single stage turret and handle each primer individually, I seem to find some unusual things.
 
I've had it happen before. A small piece of media (usually walnut hull) punched out of the flash hole during resizing/decappping finds it's way to the priming station before the stroke picks up a new primer. Hit it just right when seating the new primer and >POP< goes the weasel . . . .
 
DITTO! Slow down and poay attention to what one does and keep the tool area clean. I also do ca 200-300 per hour and inspect every case before priming and the powder level in the case.
Originally posted by magnum12pm:
I have loaded 10s of thousands on this Dillion, never had this happen. Never used anything but Federal primers. I watch my primer ram like a hawk because its true its prone to junk accumulating on the ram, do the same as mentioned blow and or brush it off repeatedly. I run about 200 an hour, because I am never in much of a hurry, and tire easily sitting at the bench, so get up move around often. The strange thing to me is the primer looks perfectly seated and no damage of any kind on seated primer, look just like everyone I load and shoot all the time. I had just completely stipped and cleaned the primer assembly like new as I had just finished 1000 38specials, without a hitch. I'm not a newby at this so I am preplexed. The second one that went off didn't scare me, since I was already deaf
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I keep an old tooth brush next to my press and clean the primer punch as it gets debris on it.

Call or Email Dillon, they are terrific. I just checked the help guide and it didn't mention this problem.
 
Originally posted by magnum12pm:
I was wearing eye protection, but still scared the crap out me!
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I will get a couple of pictures up tomorrow, as my daughter is in Cleveland this evening at the Indians game. She has the camera that takes super close ups.
Originally posted by Rolando:
Did you have your eye protection on??
 
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