I have been having a problem with high primers for sometime and judging from the internet posts, including this forum, I was not the only one.
I did some checking and I have come up with a couple of opinions that I would like to share, not implying that these are the only reasons for the problem given the many variables including primer diameter and case primer pocket diameter. I have run into some European pockets and primers that are smaller than US but that's not what this post is about.
What I found is that in my LNL, if the primer is perfectly aligned with the primer pocket, it will go in with a firm push and it will be flush or below.
The problem is that to be aligned, the little balls under the shell plate must be fully in the little holes with no play. If the balls are not fully engaged, they allow a very small misalignment between the case and the primer.
There are some reasons why the little balls don't engage fully.
The ball doesn't stick out far enough because the owner pushed them back to avoid powder spilling when the shell plate snaps in to position or bad factory installation etc.
The other reason is a shell plate with too much up and down play that allows the little balls to engage partially. This problem could be the result of a mismatch between the sub plate and the drive hub.
The thickness of the drive hub flange controls the position of the sub plate and if the flange is not thick enough, the shell plate is not held firm against the sub plate and the balls don't engage fully.
Some people resolve this problem by adding shims on the drive hub flange, I called Hornady and they do make at least one more drive hub with thicker flange which they shipped to me for free.
I no longer have the problem, unless I fail to push the handle firmly enough forward. The LNL doesn't have great leverage when it comes to seating the primer.
Let me know if you need additional information.
I did some checking and I have come up with a couple of opinions that I would like to share, not implying that these are the only reasons for the problem given the many variables including primer diameter and case primer pocket diameter. I have run into some European pockets and primers that are smaller than US but that's not what this post is about.
What I found is that in my LNL, if the primer is perfectly aligned with the primer pocket, it will go in with a firm push and it will be flush or below.
The problem is that to be aligned, the little balls under the shell plate must be fully in the little holes with no play. If the balls are not fully engaged, they allow a very small misalignment between the case and the primer.
There are some reasons why the little balls don't engage fully.
The ball doesn't stick out far enough because the owner pushed them back to avoid powder spilling when the shell plate snaps in to position or bad factory installation etc.
The other reason is a shell plate with too much up and down play that allows the little balls to engage partially. This problem could be the result of a mismatch between the sub plate and the drive hub.
The thickness of the drive hub flange controls the position of the sub plate and if the flange is not thick enough, the shell plate is not held firm against the sub plate and the balls don't engage fully.
Some people resolve this problem by adding shims on the drive hub flange, I called Hornady and they do make at least one more drive hub with thicker flange which they shipped to me for free.
I no longer have the problem, unless I fail to push the handle firmly enough forward. The LNL doesn't have great leverage when it comes to seating the primer.
Let me know if you need additional information.