OK, bullet looseness understood now.
Your neck-sizing die is apparently a trifle oversized, your brass a bit thin, or the bullets a bit undersized. It may be a combination of all of these that make the bullets loose in the assembled cartridge.
Did you use parafin or sizing lube before driving the fired case into the sizing die? It should be okay to skip the mouth belling step if you are not using lead bullets, but the sized case should be too tight to insert the jacketed bullets by hand. The seating step (after priming and powder charging, of course) uses the die body to align the bullet, and it is pressed into place using the top punch.
You might want to try another brand and weight of bullet. Try the traditional 250-255 grain lead RN or SWC. The old .45 Colt should shoot beautifully using that and 8.0 grains of Unique.
Don't worry about the uneven crimp. The next firing irons it out, and you should get several reloads out of one case.