What are these imperfections called?

[twcrowe12]

Hey all, I finally got to cast some bullets from my new rcbs die the other day and I was getting these weird imperfections near the tip. I've seen a thread on them somewhere before but google was of no help to me. What are these imperfections called and what causes them? This is the mold: http://shop.rcbs.com/Products/Bullet-Ca ... L-554.aspx

[wlc]

Finning, or flashing. I call it finning. I've got one rcbs mold that will do that from time to time.

[twcrowe12]

Mine is doing is every cast and at every lead / mold temperature combination I can think of.

[80hp]

Mine is doing is every cast and at every lead / mold temperature combination I can think of.

This is caused by the mold not closing properly.
Carefully clean the mold, inspect it for anything that would prevent it from closing.
Close the mold and inspect the joint between the two halves. They should fit together perfectly.
Also, the mold blocks should fit loosely on the handles so the blocks can align themselves.
M.

[oldpapps]

Be'en an old hill boy, we called em 'hairs'.

Two things.
The lead/mold got way too hot and the lead flowed into the air vents, thus the frosting of the bullet body and the small hairs.
Next is some of the hairs break off and stick to the mold, next pour, the flow is greater and the hairs are bigger. This continues until the hairs become more of fins as the mold can't close fully.

Full clean the mold blocks. It isn't easy, it the same as trying to clean leading out of a barrel. Great care not to scratch the blocks, think frying pan. My cousin, rest his sole, always though the blocks should be 'tempered', like a frying pan. I never did it and had no problems.

Your lead is/was way too hot and you continued until the molds were too. They could warp and that would not be good.

On the plus side, I always found the greatest consistency with heavily frosted bullets. They seamed to shoot better (more accurately) for me. This was and is my perception and most likely wrong.

Get a lead thermometer.

Load with care,

OSOK

[twcrowe12]

Thanks for all the replies guys. When I get home after exams I'll go through the mold very carefully and thoroughly clean it. I thought I had done a good job with a toothbrush and dawn right out of the package but we'll see what happens when I get personal with it.

[twcrowe12]

Thanks for all the replies guys. When I get home after exams I'll go through the mold very carefully and thoroughly clean it. I thought I had done a good job with a toothbrush and dawn right out of the package but we'll see what happens when I get personal with it.

[johnfrommd]

If you put your mold block against the spout of the bottom pour pot this will also occur. Once you get up to casting temp, you should use as low a flow as you can when filling the mold. Keep the mold about 3/4 of an inch below the spout and let it puddle so you get a good sprue. Casting slower makes better bullets with less culls.

Regards,

John

[Overton-AR]

If you put your mold block against the spout of the bottom pour pot this will also occur. Once you get up to casting temp, you should use as low a flow as you can when filling the mold. Keep the mold about 3/4 of an inch below the spout and let it puddle so you get a good sprue. Casting slower makes better bullets with less culls.

Regards,

John

I have to agree with this. SLOW FLOW = SMOOTH BULLETS.

[r.tenorio671]

....back when I used to cast for 9mm & 45ACP with my Lee molds I used to "smoke" the aluminum molds and that had a positive effect on bullet release and cast results. Used a Zippo lighter flame to "carbon coat" the inside of the mold the same way we would "smoke" front sights...... YMMV

...but to answer your original question, you have molten lead "leaking" between the mold halves; check for proper closure/alignment, pivot pin anomalies, obstructions on inner portion of mold halves.