Those National balls are cast, and I have bought 500 each, .380 and .451.
Bad balls, to my eye. Mould halves not indexed, .451 balls mike .440 to .471 at the split. .380 are not as bad, but still not round, partings are misaligned.
Have lots of swaged ball left, and my own Lee cast, so have not shot any of theirs. Have to seat one and see if it shaves a decent ring. I fear not, with that much misalignment. Can't seat them on their side with the sprue cut to the side either, that's even worse, 1/4 inch flat, near 1/32 cut off the ball.
Cheers,
George