Help w/new mold throwing larger boolits.

[BillyBoolit]

Background-
I've been casting pistol boolits since I was a kid, roughly well... a fed decades. I have been using lee 6 cavity molds and crank them out in large numbers. I'm not super anal about my boolits, I usually cast for quantity over quality. That said I've always been pleased with my end product. After casting, I powder coat them with a shake and bake method and then run them through my Star Sizer. The only limitation is how tired my arm gets as they fly through the sizer. I've casted 9mm, .40 and .45. The last few years it has been range scrap cleaned into ingots, then into the 20lbs drip o matic.

The problem-
I recently purchased a NOE 5 cavity, aluminum 402-181-RN. I cast about 1800 and walked away. When time allowed I cam back and tried to run them through the sizer and ****! They were TIGHT, so TIGHT I slugged a few in the sizer. Ok, so I read and learn they get harder for a few days after casting. So I cast a few and as soon as I can handle them I try them in the sizer, and while they go through, they are only slightly less tight. They are measuring around 4035 404ish and I'm trying to get them down to the 401 sizing die I have. Keep in mind this is W/out powder coat. ALL my other lee bullets get coated and then sized like **** through a goose.

Can anyone tell me what is going on with this new mold and why they are throwing so large? I have not changed the temp/aloy/or the casting socks I wear. I would simply go back to my lee mold but that is a TC and I want the RN (and I spent a c note on the NOE.

I apologize if this has been covered, I know it probably has, but I've read and read and read and can't figure this mold out. Any help would be appreciated.

[Conditor22]

Harder alloy = larger boolit that is also harder to size

use some case lube on your boolits to make sizing easier

or you can get HiTek boolit lube here http://hi-performancebulletcoatings.com/sizing-lube/
also works great for PC'd boolits

looks like you've been lurking for a while, welcome to posting

[Taterhead]

The NOE molds that I've had threw bullets that were a little girthy, not unlike what you're experiencing. Seems like they want to ensure that you'll contact your sizer and bias tolerances in that direction.

[mehavey]

Also, cooler molds cast larger.
What temp are you casting?

[Edward]

Like you"ve heard already it"s to hard an alloy and for sizing do it right after casting (lot easier)

[Rizzo]

This issue is interesting to me.
I too have experienced "wider" bullets than what the mold diameter states.
That is why I size all of my cast bullets. (yeah, I know...boolits!)

What is happening?
It seems that the lead/alloy of the bullet must be expanding after being released from the mold while it cools.
Assuming the mold specs are accurate, what else could it be?

[Conditor22]

http://www.lasc.us/CastBulletNotes.htm

[JonB_in_Glencoe]

I only many NOE molds.
With my alloy and casting technique, Most of them drop a boolit .001 to .002 larger than spec. Generally I find this ideal.

Hint, if you cast with a HOT mold, where the boolits drop frosty-they will drop a little smaller, than they would when casting with a cooler mold-where the boolits drop shiney.