Here's the test again for crimp:
Stand about 8 feet away from a blank piece of heavy target paper (turn the target around, so you see the non-printed side). Fire a shot (at the paper)..
If you only see a hole, crimp is good.
If you see a hole, with a neat smoky gray spiral shape around the hole, the crimp is too loose. The spiral is unburned powder that followed the bullet down the bore, hence the spiraling.
Make sure you bell mouth the case enough before inserting the lead bullet. Here's that test: Push the bullet LIGHTLY into the belled mouth of the case. Invert it upside down, and shake. The bullet should stay in place if properly bell mouthed. Don't over bell though (trumpet shape)... Too much belling will over stretch the brass, and lead to premature splitting of the brass....
Are these pre-lubed bullets? Some color grease lube in the groove(s)??? If so, some smoke is expected.
If they are not pre-lubed, then you need to lube them. How is a function of which type of grease grooves you have.
The "flakes" you have on the bench... what are those made of? Are they powder? Lead?