how are you guys priming 378, 460 500 a-square cases, got all fired up to reload, have a lee priming tool with rigby case holder which should work, and doesnt, case will not even fit into the tool, was loyal with it for years as i watched world champion shooters us it during competitions Ha! What do the experts use?

I use the primming attachment on my RCBS Rock chucker.

Good luck, Tony

Rigby rim diameter is not the same as the big Weatherby cases.

Either buy a Weatherby shellholder for the priming tool or prime in the press.

You just need the Weatherby shell holder. I have never used the Lee though.

When I had the Weatherby's and cases I used either the primer on the Redding press or the Sinclair hand priming tool which incidentally uses the Lee style shellholderss.

I use the RCBS automatic priming tool. Each primer tube holds over fifty primers. the priming "press" uses standard shell holders. You feel the primer seating and have complete control of the force and seating depth. It is bench mounted.
I've tried them all,still use this one as the tool for my reloading.