Been waiting on these!
Matt Dubber mentioned in one of his videos (I think it was him?), when he was at the FX factory doing testing that not many of the .30 slugs on the market were the right diameter for FX barrels. My storage box full of inaccurate .30 slugs seems to agree. Its great to see two diameters offered in both .30 and .25 cal finally. This will help the larger calibers catch up to .22 in the slug game.