Tool to measure squareness of bullet base squareness

[W.R.Buchanan]

Seems that could be fixed pretty easily.

Sometimes I have found that people make things into problems that really aren't problems at all if they just looked a little closer.

Randy

[MtGun44]

How would it get out of square? Neither cherry method or lathe
boring can produce a mold cavity with an asymmetric base.

Bill

[HNSB]

If the block isn't faced in the same operation as the cavity is cut, it could be out of square.

[W.R.Buchanan]

The blocks are Blanchard ground to size and matched before they are cut by the Cherry method. If they are not square they probably wouldn't fit into the fixture and close properly.

Whereas there could be situation where the blocks are not in the fixture perfectly like if a chip was under it, I think this is unlikely since anyone who is making moulds should be a decent machinist.

With the high end custom moulds the idea of an out of square base is just something you're not going to see very often. most of the CNC guys are actually cutting each half of the mould independently and if the blocks weren't perfect they simply wouldn't go back together to make a round boolit.

This operation really amazes me.

Randy

[detox]

Here is Veral Smiths trick:

To square bullet bases on both gas check and plainbase, have the lift out plug machined concave. I turned stem in cordless drill, then gound stem concave using a Dremel with small medium grit sanding drum.

Lyman or H&I sizers have a concave end machined in allready, but their stem has a looser .001 fit in die. My RCBS versions have a tighter .0005 fit.

When you size, press down at the bottom of the stroke until the liftout plug prints a ring around most of the perimeter of the bullets base. Not much force is needed for soft 20/1 alloy. You do not want to deform bullet whan doing this.

[detox]

Another method would be turning bullets in 1/2" drill press to grind bases square/true on sandpaper. Most drill presses have a built in adjustable stop for repeatability. Weigh bullets as you go.

Over thinking....