I have found exactly the opposite in that rounded followers always work the best for me and every other Bullseye shooter I know but to each his own. I would take a look at the extractor slot to see if something in there is holding up the case rim from sliding upward. Also polish the bottom of that extractor slot. If anything causes the head to stop sliding, you get a jam just like what you have.
As to the length, do the plunk test. Take the barrel out of the slide and drop in one of your loaded rounds. The case head should be slightly short or at most dead flush with the end of the barrel hood. If it is, your length is good to go. Are you using a taper or roll crimp? If it is a taper crimp (as it should be), what does you crimp measure. I would recommend .468.
Let us know how it goes please
Phil
