Sure. We use a punch and backing die combination. The punch is a hardened piece of carbide the diameter the flash hole needs to be. For large rifle, .080". For our small rifle, .060". The backing stem, which is also carbide to hold its' edge, is inserted into the mouth of the casing and contacts the inside of the bottom of the casing. The casing is then driven, by the backing stem, onto an alignment guide which contains the carbide punch. The way we have improved the punching operation since Larry received his casings, is by designing a more accurate guide bushing, that the casing is pushed on to, so the flash hole is more centered in the primer pocket. Before the new upgrade, from time to time you could get a casing with a flash hole out of center by about .000" - .015". Since the improvement we are now about .000 - .004"
If I'm reading this right the backing stem would have a hole in the middle to accommodate the punched out brass bit and the tip of the punch as it comes through. The improvement of the guide bushing allowing for better control of the hole location would then allow for a smaller diameter hole in the backing stem. This in turn would lead to a cleaner edged hole and less dishing of the bottom of the primer side of the primer pocket.
