I used my Lyman case trimmer tonight for the first time. Seemed to trim .223 brass nice and square. However, when I trimmed .308 brass I often got scalloped edges. Am I doing something wrong, or is the trimmer at fault?

The .308 brass was Winchester (PowerPoint), and it seemed to have a miliary crimp. Could that be causing it?

Dave,

I had this happen when trimming .300 Ultra and .30'06 down to 8x60mm. I had to use a drill motor chucked to the shaft of my RCBS trimmer. I believe it has to do with the impulses of the hand cranking the shaft, no matter how careful I tried, it still happened. It id NOT happen on any of my other cases in various calibers. Weird.

I have had the same thing happen to me! My remedy was to lighten up on the horizontal pressure applied while turning the crank. Just don't be quite so aggressive and slow down, your problem will probably go away.
Good luck; Chuck

[ 08-12-2003, 21:30: Message edited by: Chuck White ]