So, how do you guys adjust them initially?
The more I play with this, I'm wondering if the above posters are right about it being an alignment issue. It's almost like the bullet may not be going in completely straight.
These days I load on a progressive but I had moved away from the Lee expander die to a Lyman M die on my single stage. The Lyman M die solved a lot of problems for me as it made it possible for me to set the bullet straighter.
I pulled my RockChucker out storage today to do some case trimming. Picked out my Lee 45 ACP dies too to run through what I remembered of when I used those dies. For lead and plated , I set my Lee expander to give me about .01 to .015 flare so that the base of my projectile will sit about 1/16 of an inch into the case and the projectile sits as straight as possible. I also size and crimp in separate steps.
I do not follow the Lee FCD instructions. Instead, I set the base of the die to touch the shell case and back it out about 1/8 of a turn. The carbide sizing ring on my Lee FCD alone is generally good enough to take a light flare off the case so if the rounds plunk without tightening the crimping stem you are good to go. Sometimes I need to add more crimp. Then I will unscrew the crimping stem so that it can not touch a round. I take a factory round, or, in my case, a previously built dummy template round, with a crimp of about .4725 ish to 4.73, set the round into the shell holder and raise the ram. Once the ram has lifted the round into the FCD I turn down the crimping stem until it kisses the case and then lower the ram and tweak the stem slightly tighter. I then use a new dummy round to test my crimp setting. If the resulting crimp on loaded rounds is about .472 and the new dummy plunks okay I call it good.
As to COL for a new-to-me bullet without published data, I go as long as possible. I estimate my COL by using my barrel. I hold the barrel vertically, drop in an unloaded projectile then insert a case so that it rests on the bullet's base. I then mark the case where it meets the end of the hood (1911 barrel). Remove the case and bullet. Measure the length of the bullet. Measure the case to the mark and add those measurements, I back that measurement off a bit and make trial dummy rounds and see if I can tell which ones seem the best by taking the COL of the first dummy that plunks okay. I can usually figure out a starting COL with fewer than 5 dummies. If I haven't overcrimped the dummies, I will pull them and load them.
All that said, I have better accuracy with lead, coated, or jacketed than I do with plated but I went through a thousand or so rounds of plated to figure that out.