Commercial cast bullets not sized correctly?

[Hogstir]

I have 2 45 colt rifles I decided to shoot cast bullets in.
I ordered bullets from a number of commercial manufactures like Beartooth, Cast Performance and Missouri.
All the bullets I ordered were supposed to be .452 but they all measure out at .453.
It’s not my calipers as my jacketed bullets all measure out exactly as they are marked and the slugs in my slugging kit all measured as marked.
Do cast bullets tend to expand over time after being sized?

[John Boy]

Do cast bullets tend to expand over time after being sized?
No, and would presume the bullets are as cast. The alloy determines the as cast bullet size and 0.001 is within the bullet molds specification of 0.452.
Plus, a 0.001 over diameter is a non issue

[swheeler]

I have 2 45 colt rifles I decided to shoot cast bullets in.
I ordered bullets from a number of commercial manufactures like Beartooth, Cast Performance and Missouri.
All the bullets I ordered were supposed to be .452 but they all measure out at .453.
It’s not my calipers as my jacketed bullets all measure out exactly as they are marked and the slugs in my slugging kit all measured as marked.
Do cast bullets tend to expand over time after being sized?

Yes with antimony alloys especially when sized immediately after casting, they'll grow as they age up.

[Grmps]

I would say NO. Being commercial casters, they size the boolits before shipping and they should compensate for any shrinkage/expansion after sizing.
You should get the size you order.
.001 over usually won't be a problem.

The following info might help.

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

https://i.imgur.com/QtNXl4E.jpg

[Hogstir]

My rifles both have a groove diameter of .451 so I assume that these bullets measuring out at .453 should be should be ok to use?

[Grmps]

I would say YES But The only way to be 100% sure with your rifle is to try them.

[runfiverun]

I will say yes.

look at the chart above.
see how more antimony/tin makes a larger bullet in the same mold?
yeah magic...

[tazman]

I remember reading a thread about cast boolits growing over time about 2 years ago. The person had taken the time to measure and catalogue the results over a period of several weeks/months and included the boolit hardness in the test as well.
I don't remember all the details as far as water dropping or specific alloy since the person tested several scenarios, but I do remember that the boolits grew somewhat. As I recall, it wasn't a lot. Probably less than .001, but they did grow.