If you look into the grooves of the second one, you see the metall that was on the bands beeing pushed into the grooves and building them up to bore size.

On the first one the only trace of the bands is the metall thats gotten pushed sideways into the grooves under the rifling.

At least thats what it looks like without seeing the bullets live, but i dont see the shaft of the second beeing engraved as heavy like the first one.