Feathers on boolits

[WARD O]

I recently acquired two new RCBS moulds, 35 200 FN, and 32 98 SWC, cleaned and preheated them and gave them a quick test run yesterday. Casting straight WW at about 750 degrees, the 32 looked very nice and bullets dropped right out. On the 35 pretty much all of the boolits were coming out with significant feathers. I tried looking very close at the mould face and found nothing that was stopping it from closing tightly. I could not see light through it in any direction when the handles were tightly closed. These little lead wires would run out on both sides of the boolits at least half its length. It seemed to affect both of the cavities.

What am I doing wrong?

Thanks
Ward

[Jon]

Check around the alignment pins for gunk. Try holding a flashlight on the other side of the mold to see if you can see any light peeking though. There must be something there keeping them from closing all the way.

[Calamity Jake]

The vent lines are too deep, RCBS has an ongoing problem with this.
I have sent a number of molds back because of it.

Lowering the mold temp will help.

[AZ-Stew]

In addition to lowering the amount of tin in your alloy and lowering casting temp, as suggested above, another factor is whether you are ladle casting or holding the mould against the spout of a bottom pour pot. Either will add pressure to the alloy entering the mould and force it out the vent lines. Try pouring your boolits with space between the ladle or pot spout and the top of the mould.

Regards,

Stew

[44man]

Hey, they put feathers on arrows for a reason you know! :bigsmyl2::bigsmyl2:
Just scrape them off with your finger nail, nothing to worry about.

[beagle]

I'd guess the moulds are too hot. Easy to back off on the temps and see./beagle

[WARD O]

I had been thinking that lowering the temp would be my first move.

So to lower the tin in my WW, I would try adding lead? Like maybe try 2/3 WW and 1/3 pure lead or ?

I know these feathers come off easy as that is what I did yesterday - I just thought it would be easier yet if I didn't put them there to begin with.....

Ward