Re: Lee factory crimping die experiences
I have, and not really. It has a place, but I don't think better accuracy is a reasonable demand. I used it with .308, .223, and .30-'06.
I would use it with semiautos, when and if I had solid evidence of bullet setback in the magazine. Beyond that, it's not needed.
I tried and tried to demonstrate an accuracy benefit from it, but never found anything that constituted convincing evidence.
If you overdo the crimp depth, you're at least as likely to hurt accuracy as anything positive you could do by using it correctly. Using it correctly takes a lot less crimp than most folks might think. If it's needed at all, something is better than nothing, and it doesn't take much to make it worse than nothing.
Greg