Boolit roundness as dropped from the mould?

[Russel Nash]

I casted a bunch of .40 cal -ish boolits from a Lyman mould about 15 years ago.

I never got around to Sizing them.

They had been sitting in a GI ammo can this whole time.

They are about 177 to 178-ish grains:

IMG_8161.jpg

I was going to try my second attempt, ever, at shake and bake powder coating last night.

But, first I thought it might be a good idea to measure about 10 of them for roundness.

Now, I either suck at measuring stuff with digital calipers….or????

Some bullets would measure “north south” at say .403”

Then I would turn them “east west” and the calipers would read say .407”

I could swear there was one that came up as .412”

For grins and giggles last night, I ran about 150 of them through my Lee push through sizer that is 0.401”.

Some went through easy enough.

Some required more gumption.

So I gotta ask….is getting more round boolits strictly up to the mould?

Or can it be strictly operator error?

Or some combination of both?

[Recycled bullet]

I couldn't really tell in your picture, can you please take a zoomed in focused bright photograph showing the bullets?

I'll just say that if you remelt and recast them before you powder coat them it stinks a lot less.

If the mold is not hot enough when you are casting then the molten lead will freeze in an inconsistent pattern usually resulting in random voids, blurry rounded driving bands and edges and ultimately poor fill out.

[justindad]

.403” to .407” can happen. The mold block might not have fully closed. Or, the cavities in the two blocks might not be in alignment. There might be other ways for that to happen too.

[country gent]

In a way it is a function of the blocks in that if the cavities arnt round and aligned to start with then you wont ever get round bullets from it. But dirt a burr or misaligned pins can also have an effect here. Would help inside of east west you gave on the parting line and 90*. This would show misaligned blocks and blocks not closed completely.
Moulds can be lapped to make very round bullets but you cant lap down in size so in you issue 403-407 you would have to lap up to 407/408 .

Depending on the way is off look for small burrs misaligned pins improper seating.

I would size them down to round before powder coating.

[405grain]

I would suggest that you size these bullets both before and then after powder coating. If you PC them as is, and then try to size them they might become way too big and wold require way too much force to size. If they come out OK, then just shoot them.

On your mold: close those mold blocks in your handles just like you would if you were going to cast with them. Now hold the mold up to a light and look inside the cavities. Do you see any light between the mold halves? If you do, it means that your molds aren't closing completely. Check to see what's wrong. It could be some tiny lead splatter between the mold blocks, or sometimes the alignment pins can peen around the edges of the alignment holes. If there is splatter on the face of the mold blocks remove it. Don't use anything that's harder than the molds; toothpick or some kind of plastic scribe should work. (never, ever, use a wire brush on a set of bullet molds). If the edges of the alignment holes have been peened, ever so slightly chamfer the holes to remove just the slightest amount of material until the mold blocks close fully.

[JonB_in_Glencoe]

asking respectfully, did you know what you were doing 15 years ago?
.
Depending on alloy, bullets will grow in dimension, in a couple years time, but same batch should increase same amount.
.
Because you had varied results during sizing, one thing to do, is separate a group of bullets that measure the same.
then do a weight test to see if the larger ones are heavier. That would lead me to believe you weren't closing the mold uniformly or correctly
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In all honestly, I'd melt them and cast some new ones.

[JSnover]

Moulds can be lapped to make very round bullets but you cant lap down in size so in you issue 403-407 you would have to lap up to 407/408 .

That was my thought. If Russel's mold block faces are clean and they close good and tight, lapping may be the thing to do. Then maybe play with the alloy or temperature to drop them a bit smaller if he wants.

[gwpercle]

The way they were stored didn't help ... just dumped helter skelter into a steel ammo can and bumped around for 15 years ... that has done nothing to promote roundness . They were probably a lot more rounder 15 years ago but they got bent outta shape some over all that time .
Size them for roundness and Consistency ... all a nice .401" diameter...
and stack the boolits neatly for 15 year storage !
Gary

[JonB_in_Glencoe]

The way they were stored didn't help ... just dumped helter skelter into a steel ammo can and bumped around for 15 years ... that has done nothing to promote roundness . They were probably a lot more rounder 15 years ago but they got bent outta shape some over all that time .
Size them for roundness and Consistency ... all a nice .401" diameter...
and stack the boolits neatly for 15 year storage !
Gary

I really hope you are joking.