Buckshot What da ya think of this HP mold

[TCLouis]

idea.
Using a common quality drill press and a pretty decent drill viseto drill a hole for the Hp rod.

Line the DC mold up using a countersink or denter drill, start the hole with a smaller center drill and then finishing with bit size of choice.

It is based on making a 158 grain 0.358" DC boolit mold useful.

Think this will be accurate enough, of do I have to chuck it up, indicate it in, and then drill using drill in the tailstock?

[crazy mark]

Not Buckshot. It can be done if you have patience. You will have to be careful when you drill the pilot starting hole. I have done SP's this way and one RN but I ended up drilling the hole about .003 off. Still shot OK. Another way to start is grind a center punch to just slide inside the mould and see if you can hit center. Remeber not all blocks are cut parallel or the cavity straight to begin with. I made Beagle a centering jig for a older obsolete mould he wanted to HP. It fit into the cavity and basically was a hardened steel bullet with a hole in the center Mark

[Buckshot]

............Sorry, I just saw the post. It's all in the setup whatever you use. I don't know what 'common quality' equates to in a drill press :-). A really good drill press will have 2 bearings on the quill. Top and bottom. A lot of cheaper drill presses have only one bearing. My grandfather had an old Craftsman DP that was as stout as a milling machine. My neighbor has a recent import floor model you can grab the chuck on and rock the quill. Not good.

If your quill has play in it then chuck it up in the lathe. Actually, if you have a lathe and a 4 jaw, setting it up there would take no longer then messing with a drill press, and probably less.

Assuming no lathe and a good DP, you have to make sure the bed plate and vise are perpendicular to the quill's axis. If it is, I would use at bare minimum a center drill (not running) to come down and center the base opening of the cavity. Then lock down the vise to the bed. Recheck the centering.

With a center drill small enough to enter the cavity, run it down to touch and then while holding it lightly against the nose of the cavity turn the pully or rotate the chuck by hand a turn or two. Withdraw the bit and look into the cavity with a bright light to see where the center drill marked. If you can't see the mark for whatever reason, take it out of the vise to check it. Naturally you'll have to put it back and re-center it again, but at least you KNOW the setup is right.

If it appears to be centered on the parting line use the centerdrill to start the hole and then use your drill bit. The bit will want to follow the parting line so if it is actually off a couple thou and the bit is small enough it should correct itself.

The biggest danger is drilling the HP pin hole at an angle to the cavity. Someone sent me a mould once that had been done in a DP I guess. The hole was right on the parting line but slightly tipped. I had to use a 3/16 centercutting endmill to clean up the hole and then make a HP pin.

..................Buckshot