Don't do what I did.

[corbanzo]

I was loading some .40SW ammo, didn't crimp like I should of, just ran the top of the brass through the carbide on my crimp die to take away the bell.  Had about 4 loading failures in 100 rounds.  The brass lip was catching on the top of the chamber.  Usually, the hollow point bullets I use change the angle enough that this wouldn't be a problem, but these were round nose lead bullets which means the brass will hit the chamber at a sharp angle, meaning that a crimp is necessary to make it chamber smoothly.  Problem solved....

[Dusty Miller]

I won't do that, I promise.

[corbanzo]

Yeah.... especially cause that was with a lot of 400 rounds.... good thing working hard (out of monotany) you can crimp that in 10-15 minutes or so.....

[jhalcott]

  I wish you'd have said some thing sooner! I did some thing like that with  some .45 auto ammo. had a bunch that did not get crimped enough, there was a bit of the "bell' left. It caused a feeding problem in about 1 or 2 rounds in about 20. I had  not reset the dies properly after cleaning them. I also needed the ammo for a shoot the next day!