I ran mag primers as an exparament. Some guys have said the extra umph can give better ignition leading to lower sd’s/es
Not enough rounds logged to know if that’s true or not.
If shooting the cup as a team...both shooters engage the targets at the same time and as soon as they have all been hit twice or round count is met or stage time limit is reached...stage is complete ?
This is how I read the description at in motion website