I took the part out that the primer drops into and put a chamfer in it. Never did it again

 

As Tom said above, there are 2 donut shaped parts the primers fall into. The original one is flat on both sides. The new one is flat on the bottom and chamferred on the top to help the primers drop into the hole. You can buy a new one or try putting some graphite powder on the top surface of your old one, if that's what you have. What style have you got?

Picture?

 

Guys,
There are a few things that can cause this issue.
1. Improper alignment of the primer feed tube.
2. Improper timing of when the primer feeder drops the primer.
3. Improper mounting of the primer feeder
4. Carrier moves out of sequence.
5. Carrier is bent or worn out.
These are just a few things that can cause this problem. There are others.
I would suggest removing all shells, powder & shot from your machine. Cycle your machine with only the primer and deprimer function working. Pay very close attention to what is happening. If everything is properly adjusted, this issue does not occur. Watch to see why the primer doesn't drop into the pad properly.
Best of luck,

 

Guys,
There are a few things that can cause this issue.
1. Improper alignment of the primer feed tube.
2. Improper timing of when the primer feeder drops the primer.
3. Improper mounting of the primer feeder
4. Carrier moves out of sequence.
5. Carrier is bent or worn out.
These are just a few things that can cause this problem. There are others.
I would suggest removing all shells, powder & shot from your machine. Cycle your machine with only the primer and deprimer function working. Pay very close attention to what is happening. If everything is properly adjusted, this issue does not occur. Watch to see why the primer doesn't drop into the pad properly.
Best of luck,

Definitely right about all the possible cause and effects.
I tried to narrow it to specific holes, and the timing of the drop. I feel like the primer dropping down into the hole at st2 is inconsistent. The primer looks like it is flopping back and forth as the Carrier passes over. When the primer is rattling around it seems to catch the back side of the hole and pulls it up.

Once I thought the collet was sticking some causing a POP. This could send a slide hammer affect into the bottom of the machine causing the primer to jump out of the hole as the Carrier is still moving making the jam condition.

 

I had this problem with my 9000 that is set up for 7/8 ounce loads, my 1 ounce machine runs perfect. I spoke with a MEC rep at the Cardinal Center, he said to note if it happened every time or sporadically, like every sixth shell. You may have a finger, for lack of a better word, of the carrier bent up or down. I used mg1polo's technique (good advice) and stripped it down to only dropping primers. I measured the distance between the carrier and the base to make all of the fingers the same, .015 seemed to be the medium, so I tweaked them all to be as close to that as possible. Put everything back together, still did it. Swapped spring pads between the machines 1 ounce still worked perfect, 7/8 ounce still flipping primers. I was at Fin Feather Fur shortly after that, nice reloading department in the basement, and asked if they had spring pads. Got berated a little bit, why do you want one they never wear out. They had one in stock and I bought it, for $6.00 I was willing to give it a try. Got home and measured the two spring pads, both were .375 overall height but the the new ones base measurement was .150 versus the old one at .165. The new one protrudes .015 closer to the carrier. After several hundred shells it has never jammed a primer with the new spring pad.

 

I'm going to look into this. I've thought the one I had was too short.

 

I just put a chamfer in mine and it loads 7/8, 1 ounce and 1 1/8 ounce loads with no problems. Just saying