Hornady brass is typically lighter weight and more H2O capacity than others. Up to 20gr per case less (ie. 270) and 2-3 gr H2O more.
So yes, it does make a difference in velocity. My Hornady loads take +/- 2gr more of powder to achieve the same velocity. Many are therefore over book max charge value, but perfectly safe. In fact, I typically use book velocity, rather than load weight when doing load development (correcting as necessary for barrel length).
Hornady also has huge spread in case weight, like 10-11gr (I.e 270 Win 170-182 gr). However, H2O capacity is more consistent (<0.3 gr H2O spread over such a large range) - which I found quite suprising.