Drilling additional holes in size die?????

[cabezaverde]

I want to drill a couple of extra holes in one of my size dies to increase lube flow to a TL design boolit.

Anyone done this? Tips?

[crabo]

It is probably going to be hardened. When I have Lathesmith make me sizing dies, I have him put 4 or 5 holes in the larger caliber sizing dies to help with the lube flow.

[JIMinPHX]

It can be done. You either need a milling machine with a spot drill, a drill jig, or a real good center spot from a punch to get the hole in the right place. The kind of drill jig that gets used to drill sight mounting thread holes in rifle barrels would work well. You might get away with a drill press, a vice & a short split-point drill bit.

The hardest part is keeping the drill bit from walking off center. If you have the right equipment, you can do it. If you have a lot of skill & craftsmanship, you might get away with doing it with less sophisticated tools, but that would be difficult. I do that sort of thing on a Bridgeport with a spin jig, which makes it kind of easy. Sometimes, I tap threads into the holes, so I can put short set screws in them later if I decide that I don't want to use them anymore.

The commercial size dies, that I have seen, have been a little on the hard side, but not full hard. I have been able to cut them with regular high speed steel bits if I keep the feed rates & spindle speeds where they belong. I've always worked with Lyman brand size dies.

[JIMinPHX]

If you run the corner of a file over the edge of the die & the file is able to bite into it, then it is soft enough to drill with standard tools.