Thread: The answer to my 223 ES pissing and moaning?

Originally Posted by Roarless20

an update on the 6CM velocities i mentioned in my rifle on the first page:

I kept the main load the same but pulled the expander mandrel out of the F/L die, sized with the usual 2 thou bump. Then used a mandrel (actually the mandrel from a .243win Lee collet die) to expand the necks in a second stage.

The accuracy might be slightly better, which was always good but the velocity over approx 20 shots is now SD 8.5 & ES 30. So definite improvement. I'll skim turn the necks and see if that helps more (because i can and i like tinkering).

Greetings,
Expanding the case necks with a mandrel or even the standard expander button is a trick used quite often. The advantage is that the base of the case is held square with full support from the shell holder bottom rather than being dragged over the expander with only part of the rim held. You just need to decap first. Neck turning is another matter generally not thought to be much help in a factory chamber so don't do too many before testing.
GPM.