I completely agree in a semi auto. I normally just crimp them enough to remove the flair. The neck tension does hold the bullet.In my post I did say ball ammo, not HP but the concept is the same even though the numbers will vary.
That is incorrect, with semi-auto ammo the crimp is not meant to hold the bullet in place, it's only to iron out the flair. Excessive crimp can deform the bullet and effect accuracy. Neck tension should hold the bullet.
The more you tell us the more I am starting to believe all your dies are not properly adjusted. It now sounds like you are not resizing the case properly and have inadequate tension. Same thing with the crimp die, not adjusted correctly.
What I was referencing above was the plated bullets I loaded in 44 Magnum which were being shot in a revolver. The majority of the loads I've played with have required a moderate to heavy crimp to prevent the bullet from walking out of the case. I've had no issues loading 44 Mag, or any other caliber for that matter, but my experience has been that the accuracy sucks when you put a crimp on plated bullets and I've not found another way around that in 44 Mag.
I originally thought it was my die adjustment as well, but I tried to start over with them this time and I'm just not sure how they can be adjusted incorrectly. I'm adjusting them just like I have for other calibers without an issue. I'm just screwing in the sizing die until it touches the shell holder. Then for the expander die, I've tried multiple settings, but I'm expanding them enough that I can start the bullet into the case by hand. My seating die is backed out 3 full turns from the shell holder per the instructions so that it's not crimping the round at all. Then I'm using the Lee FCD which is screwed in until it touches the shell holder as the instructions say to do. Then the adjustment for the crimp is turned in between 1/2 turn to 3/4 a turn past touching the case mouth. I've tried both. Normally half a turn for other calibers has been sufficient, but it didn't seem to completely remove the flair, so I went to 3/4 a turn.