How to identify the bullet to the cavity it came out of?

[Wm Cook]

Is it possible to mark a mold (steel or aluminum) cavity so I can easily sort which bullet came out of which cavity. Example; I have a 2 cavity Lyman 265438 that drops the far cavity one grain heavier than the near cavity.

By carefully casting and separating the near from the far (drop by drop) I wind up with two bell curves when they’re sorted by weight.

The problem is that the two bell curves converge and the heaviest of the near cavity overlaps the lightest of the far cavity and I can measure the difference in group size.

Thanks for any advice, Bill.

[Winger Ed.]

Take a real small center punch and put a tiny dimple in the nose end of one side of one cavity.

Just big enough to see without changing any of the boolit's characteristics.

[country gent]

Center punch will work as will letter number punches. an o x gives a second or third option that stays even. I use a transfer punch that when buillt up with r=tape just fits the mould cavity thus keeping the dimple centered. When doing this be prepared to remove raised metal from the dimple or the mould may not seal up tight

[Wm Cook]

THANKS!!! Keeping the far and the near separated while I was casting was driving me crazy. Bill.

[Conditor22]

Leement (polish) the smaller cavity to where both cavities are the same.

[gwpercle]

THANKS!!! Keeping the far and the near separated while I was casting was driving me crazy. Bill.

So will looking for that little dimple ! In theory you are supposed to remove the dimple with your thumb nail before shooting it ... there's got to be a better solution !
Single cavity mould ? Every one would be the same ...in theory !
Gary

[stubshaft]

I have used the dimple method for years and have never had any issues with it.

[Outpost75]

Instead of prick punch dimple I have used a narrow knife blade or electric pencil and did +, -, ^ or / to identify cavities on gang molds. I tried to mark meplat of bullet if large enough on a .38 or .45 wadcutter, otherwise as close to the end of the nose as possible on a .22, or .30 cal. rifle bullet. Found it helpful on older Lyman or Ohaus cherried molds, but completely unnecessary on lathe bored Accurate molds, as they all cast identical.

[Wm Cook]

Is there an abridged version somewhere on how to polish the small cavity to where both cavities are the same? Sound like something I could mess up. Thanks, Bill.

[country gent]

You cant lement a mould for only one cavity adding tape will increase size in both cavities. Some questions are needed to be ask here To be sure what to do.

1) Where do the cavities vary at dia outside length inside the lube grooves. You need to measure the 2 bullets or better a group of each. See where they are different.

If its in the dia lapping the cavity can fix this if its the nose, inside the grooves or length. fixing this is a lot harder.

If its the dia a light lapping can be done.

Heres how. make some decent casts from each cavity.

use he opposite cavity to make the lapps. Drill a blind hole in the base and epocy a piece of 1/8" key stock 1 1/2" long in them anf let cure. You can use the blocks to hold bullet while drilling but do not break thru bullets.

You need to work slow and check often by casting some bullets and weighing measuring them.

Insert the lapp in the problem cavity and carefully close around bullet fitting it into the cavities gently. Clamp lightly in a vise or rubber band around blocks to tension. With a tap handle on stem work back and forth 1/4 turn 3-4 time and rotate 3/8 turn repeat the back and forth 3-4 times and work like this thru 3-4 rotations. Low lightly work the other cavity 1-2 back and forth 3/8 turn repeat thru 1 rotation. clean blocks good and cast some bullets, measuring them as before. Of more is needed repeat above the last time after they are the same is to start in 2nd cavity and work as before ending on the problem cavity. As I said you want to work slowly I would recommend toothpaste or auto rubbing compound as they will cut very slowly and give a very nice finish. Keep in mind lapping a bore or hole every .001 removed is .002 in size.

[pworley1]

I do the same thing with the dimple, except I put it on the drive band so the sizing die takes it off.

[Geezer in NH]

Get a single cavity mould and forget about it!