Air voids in long projectiles

[mpkunz]

Received my 311247 mould recently and just gave up for the night. Out of more 200 throws from a 5 cavity mould, not a single projectile was useable. Every one had air void problems of one sort or another. They started out wrinkly when the mould was cold and finished with the classic holes that indicate air is not escaping the cavities as the hot lead enters. I increased the temp setting but all that did was add flash problems to the air void issues.

Any ideas ?

[selmerfan]

Check your vent lines, run a razor lightly down the vent lines to clear them of any debris, chips, or blockages.

[mpkunz]

Great idea. Thanks. I'll check those tomorrow.

[geargnasher]

Check venting and ladle pour your next batch with a Rowel-type ladle, applying the spout to the sprue plate while holding the mould sideways and rotating mould and ladle together per the Lyman instructions to put a little head pressure on the alloy. This always helps long boolits and large boolits fill better compared to a bottom-pour pot.

If it's a NOE mould (5-cavity is my clue), follow Swede's instructions of bringing the mould to full casting temp and back down at least three times to "cure" the mould. He's not kidding, it makes a world of difference. Same with the Lee six-bangers.

Gear

[oneokie]

Clean the mould again.

[cbrick]

Gear nailed it.

Nothing beats a ladle poured long and skinny bullet. Some people complain how hard it is to pour 22 cal bullets, for me those are easy. The toughest ones for me were the long, skinny, heavy for caliber bullets. Tough that is until I discoved ladle pouring them, now they are no more difficult to get great bullets with a very low reject rate than any other bullet.

I now have and use four Rowells, Number 1 for two cavs and/or small bullets and number 2 for 5 and six cavities and large bullets. The other two are for smelting.

Rick

[mpkunz]

You guys received written instructions with yours ?

[cbrick]

You guys received written instructions with yours ?

Don't understand the question, with yours what?

Rick

[geargnasher]

Your NOE moulds. I don't remember for sure. I think I read Al's for break-in in one of his vendor threads.

Gear

[canyon-ghost]

Swede sends out some instruction, printed ones, with some molds. Also, try not to stir a lot of air into the melt when you flux, keep the mold low over the pot when you ladle. Don't stir.

[cbrick]

Molds huh?

I kinda thought he meant ladles . . .

Rick

[geargnasher]

If it's a NOE mould (5-cavity is my clue), follow Swede's instructions of bringing the mould to full casting temp and back down at least three times to "cure" the mould. He's not kidding, it makes a world of difference. Same with the Lee six-bangers.

Gear

Rick, I thought he was referencing this comment. Maybe not. I'm still operating under the assumption that he has an NOE mould.

Gear

[beex215]

i remember my 309 mold kept dropping bullets with lines in them. i check the mold to see if there were cracks or something. i just didnt understand. i smoked the mold to see it it would help and it did.

[JIMinPHX]

I'm working on a vent making tool. I'll post about it when I get it finished.

[mpkunz]

Swede sent me a link for the direx. I cycled the mould temp 5x, didn't matter. Still had major air voids. I examined the flat inside mating surfaces of the mould. The swirl pattern left by the fly cutter for letting out air crosses the ogives differently on each cavity, producing different problems with each cavity. I compared to my Lyman and LEE moulds which have a consisten set of parallel cuts that release air at the same point on each cavity. In some places I had a cavity surface more than 0.300" long with no air relief. I solved the problem in a matter of minutes with a fine file by making air grooves perpendicular to the cavity contour that allowed air to escape into the existing swirl pattern. Probably voided the warranty, but it works now. The swirl pattern looks cool, and might work OK on shorter bullets, but its a disaster on long bullets like this one. Problem fixed. YMMV.