vang comp question

Howdy you'all...

Here's the sitch: rem 870 wingmaster with a rifle sight 18.5" smooth bore barrel for home defense. But I like to shoot skeet every once in a while and plan to hunt birds in the future. I usually switch out to the original barrel for this: a 28" ic. I load my own shells for this, for fun and economy, and as we all know those fancy controlled spread wads are not available to reloaders for whatever reason. But I really love the idea of a short barrel with a bit of range. So I've been contemplating getting a vang comp non ported job on the short barrel. From what I've gathered, the vang comps for sure greatly improve patterns for 00 buck with a standard wad ...but I can't seem to find much information on what I can expect out of 7.5 birdshot with a standard AA wad. Does anyone have any clues?

Thanks.