With auto-bullet/boolit feeder on presses, this is a way to not have the case mouths "Bell" at the top and have bullets TIP, just as you are about to seat it.
I don't pay for high dollar case expanders, as others here do. I don't even know if the mr bulletfeeder expander insert fits in a Lee Powder charge dies. I do it myself, Better That the "stepped" mr. bulletfeeder expander.
If you have diamond dremel bits, and a high speed power drill, you can "turn" the Lee insert, like I do. And the cases never "bell out" at the mouth. Here's how:
1) Measure the dia. at the Base of the bullet of the caliber you want to reload...add 0.02"
2) Measure the dia. of the Lee powder through expander insert...until somewhere on it's "shaft" that matches that "target dia" with your calipers...an make note of that approx location.
3) Depending on the caliber you are working with, pick a power drill bit with a shank that "almost fits" into the other end of the insert. Hold the drill bit vertically on your workbench with the insert push on top. Take a hammer and tap the insert, wedging it onto the drill bit shank. Turn the drill and re-tap if expander "wobbles" too much. It doesn't need to be perfect at all, but close as you can get it. THIS WILL NOT HURT THE INSERT!...they are made of Incredibly Hard steel! And what little "scuffing" that may occur is in-line with the powder flow anyway. Chuck the cutting end of drill bit tightly.
4) Rest the drill on the bench on it's side. Any number of diamond dremel bits will work, but I generally use one that tapers to a sharp point and clamp it's shaft tight in vise grips.
5) Turn your power drill on at high speed, and push the diamond bit with a fair amount of pressure into the place you want to narrow...I always start at top and remove the bell...checking progress with calipers now and then, until the dia. is at, or even less, than the dia. you figured above.
6) Having done that, work on area just below, until all parts of the inset are at, or below the
target dia.", as mentioned above.
Below is a rough drawing of it. The Black is the shape of a Lee expander insert...Red is the areas I cut/turn off of it.
- INSERT.gif (5.35 KiB) Viewed 305 times