boolit defect

[chevyiron420]

hi folks, i want to ask your opinion of a defect i get on most of my rifle bullets from several molds. on some bullets i get a spot right at the first groove, closest to the nose, sometimes right on the leading edge of it. the boolits will vary from a small soft edge dent to the worst looking like a bit of cool lead was stuck there and the pour went around it and semi bonded. i get this on too many boolits to suit me, on several molds. and yeah, im bottom pouring from a lee pot. hotter or cooler alloy doesnt seem to matter, nore does skidding the silver stream on the spru plate.-phil[smilie=f:

[Bass Ackward]

Clean your cavities again real good and then smoke it. That should get rid of it unless it is a venting problem. You should be able to see that with a set of magnifiers if you gotem. If not, borrow your wife's sewing glasses. Use a sharp object and work away from the cavity.

[chevyiron420]

thanks B A but i dont think thats it. i have been all over the molds. i get this on about 20% of bullets cast i any of my rifle molds. it runs my reject rate way up. im thinking it may have something to do with the bottom pour but i have been experimenting with teq. to no avail yet. maybe a splash in the mold when i pour????

[cbrick]

hhmmm . . . This sounds like a problem that needs a scientific method to resolve. I just happen to have a good solid Scientific Wild As**d Guess.

Seems that more often than not there is always a drop of alloy left on the nozzle. Before filling the mould I always remove this with the edge of the sprue plate, then fill.

Could try this, perhaps your getting a drop in the cavity before you fill. Since you mention that it's most of your moulds and not just one I can't imagine what else it might be.

If you find the cure I'd be interested in knowing the answer.

Rick

[leftiye]

I know you won't like this. There could be some crap in your melt. I think of it as heavy oxide that gets in the bottom of the pot and ends up in your boolits. I'm not saying this is your problem, only that is the first thing that came to my mind.

Cure is clean alloy, well fluxed, in a clean pot. Don't add sprues or anything to your pot until you refill it. Melt your lead to refill your casting pot in another pot, flux before putting it into your casting pot. This has the added advantage of saving time as you can be remelting your sprues and rejects and additional alloy while you are casting. If you use a bottom pour pot, cover the alloy with crushed charcoal (can be used on melting pot too) = constant fluxing.

I always pour a little puddle about like a sprue before pouring a boolit to get rid of that stuff on the spout that Cbrick was mentioning.

[chevyiron420]

you know, i bet its a blob of metal from the pour spout thing, and like you said ill pour a little spru size blob before i put the mold under. maybe i should get the thing dripping good and just let it keep doing it instead of constantly adjusting on the rod valve thing!-phil

[mooman76]

Try top pouring after you get the mould up to temp and see if you have the same problem and go from there with a few of the other sujestions!

[quack1]

I get the same type defect if I don't get the little blob of lead off the nozzle with the edge of the sprue plate before I fill the mold.
If your molds are multiple cavitys, you might be getting a small splash of alloy in one cavity while filling the other. Just something else to check.