[johnsxj]

It might not be as much of an issue with 209 type primers due to how they're made but there's always a chance....

O.P.
If you've never used the Nobel 209 primers here's a couple tidbits...
Use load data that calls for regular Winchester 209 primers.
Keep in mind that Nobel 209 primers (like pretty much all European 209 primers) have a slightly larger diameter. Once you seat a euro primer in a U.S. hull, stick with the euro primers in that hull. Using a U.S. primer afterwards will have a loose fit.

 

[sharps4590]

Short answer, yes.

 

[soundguy]

It might not be as much of an issue with 209 type primers due to how they're made but there's always a chance....

O.P.
If you've never used the Nobel 209 primers here's a couple tidbits...
Use load data that calls for regular Winchester 209 primers.
Keep in mind that Nobel 209 primers (like pretty much all European 209 primers) have a slightly larger diameter. Once you seat a euro primer in a U.S. hull, stick with the euro primers in that hull. Using a U.S. primer afterwards will have a loose fit.

You can fix that loosened hull primer pocket caused by a European primer in it by running it through a MEC Super Sizer

 

[gwpercle]

Be very careful with loose primers ... the danger is in the primer "dust" !
This dust comes from the priming compound and in theory can be set off with static electricity ... I tend to hold a lot of static electricity ... I can make a blue spark jump from my finger tip by walking across the carpet , on a dry day and letting the dog sniff my outstretched index finger at 1/4 " away we both get a shock and you can see the blue spark jump ... I have no doubt this would spark the powder . Also the compound is sensitive to a blow ... if something fell and hit the powder lying on a table the blow might ignite it . We were warned not to put primers loose in a glass jar ... dropping the jar could cause a explosion ...I guess that might be sympathatic ... but primers used to come in smaller boxes ...side by side touching each other ...now they don't each primer is in it's own little recess . We have been instructed to leave primers in factory packages .
I'm not sure what you want to do ... but be careful ...primers are made to explode with a simple impact to the priming compound ... and when primers are all piled up ...that's going to get interesting .
Gary

 

[brich1646]

Years ago, maybe, in my first Lyman reloading manual, or perhaps some other article on reloading, it mentioned sympathetic ignition of primers. From what I remember, Sympathetic ignition was defined if one primer would ignite the entire package would ignite, if primers were stored loose in the same container. Kind of like spontaneous combustion.
Today primers are sold in 100/packet, with 10 packets/brick. The packets separate the primers.
The other day I found a gun shop in York, PA selling Nobel 209 primers with 1000 loose primers/zip lock bag. I did buy a zip lock bag of 1000, but wonder if this is a dangerous or sketchy practice that could result in disaster.
Has anyone else heard of sympathetic ignition, and if so, can you expand upon it?

I've heard of this myself but never experienced it. I have bought loose primers but I've always kept them in cardboard since ziploc bags can build static. Not saying a ziploc bag is capable of building enough static shock to set off a primer but it seemed silly to even take that chance. I reuse all kinds of boxes and put them in a old cardboard ammo box and never had any issues going through 5k primers that way. I have heard of ziploc baggies setting off exploding binary target powders hence why the 22 cal stuff comes with static proof bags to seperate it into. All in all I wouldn't chance a ziploc but honestly if you do I'm sure your not the first and I've never heard of any issues and I'm a 3rd generation reloader so I've had 60 plus years of reloading taught to me by two of the best men I've ever known and they never mentioned this so I'm going to say it's a rare occurrence or it's not an issue to be worried about.

 

[Santa Ron]

Re-loading for over 50 years and only had one primer issue (I am super careful and still use single stage loader). That said I was priming .45 ACP brass with Federal LPP's with my RCxx hand primer tool in our Arizona room and watching/listening to TV at the same time with my wife. A primer popped off on one of the last 4 or 5 cases, not sure why, I check to make sure it is coming out correct before in installing the brass to seat (it was fully seated). I was fine since I always point the brass away from my self however am still recovering from wife's rolling pin lumps on my head and had to throw out my shorts.