Eric, Not really sure when it's dropping it, so let me begin from the top. The chain is your timing device. If your primer is falling out before it gets to the bottom of the stroke then the chain is to short. You want to adjust it so that it drops the primer at the bottom of the stroke.
If the problem is that it's not dropping it in the hole for the primer, pull the handle all the way down and adjust the tube where it is 1/16 of an inch from the revolving plate. Tighten it good when you have the proper depth and then while holding close to bracket bend it so it's centered over the drop hole. Jackie B.
"Sometimes the bracket holding the tube has to be bent a little to align the bottom of the tube with the rotating plate hole. A crescent wrench and a little persuasion on the bracket in which ever direction necessary will fix a lot of problems. The bracket can be bent in any direction to get it aligned properly. Just make sure the bracket bolt is tight when doing this. If you don't have a MEC loader manual, give them a call and you'll have one. Timing the primer drop is also important for easy loading which is made by adding or subtracting links on the chain. Hap"
I upgrade to the new 200 primer assembly several years ago. After adjusting and bending, I also found that a washer (spacer) to lower the drop tube until it JUST touches the indexing plate, and setting the cam timing to drop later (at the bottom of the stroke), works best for me.