Hello, Knarley:
Yep, Lyman moulds can be significantly out-of-round. I have seen 50 caliber Sharps ones .008" out.
I suggest you contact Accurate Bullet Molds in Salt Lake City. Accurate bores its moulds. The website has all the technical info you will need. The owner is, by his description, deaf, so no calls or voicemails. I have several of Accurate's moulds and all are great.
Alternatively, you can call Buffalo Bullets/Arms out west. Speak to Dave Gullo, who is a respected BPCR shooter.
Smiles,
El Supremo/Kevin Tinny