You didn't mention what type reloading dies you are using BUT more case necks are pulled off center by the expander button than by any other cause. This is the reason why high grade bench rest dies don't have expander buttons to add to your problems.

[img width=600 height=210]http://i122.photobucket.com/albums/o254/bigedp51/misalignment-a.jpg[/img]

[img width=284 height=450]http://i122.photobucket.com/albums/o254/bigedp51/misalignment-b.jpg[/img]

Even a bur or ding in the extractor groove of the case and pull your case off center and cause the neck to be misaligned. A simple Lee loader can be a poor mans costly bench rest die, remember 97% of all errors are human errors and only 3% are mechanical failures.

[img width=282 height=450]http://i122.photobucket.com/albums/o254/bigedp51/misalignment-c.jpg[/img]

Also partial resizing with full length dies promotes better accuracy than neck sizing.

If you get a runout gauge check for banana shaped cases, warped cases with the base of the case not 90 degrees to the axis of the bore. This is caused by cases that do not have uniform thickness and one side of the case expands more when fired. When these cases are reloaded and fired the case neck is no longer aligned with the bore.

Stay with your present load and work out the bugs, changing cases or the load now will only confuses the issue........KISS (keep it simple stupid)