Lil gun worked great with 40gn vmax. Once fired hornet brass yields the most volume. Only size mine down to where base of bullet stops. Remainder of case fills chamber. 1 grain art a time during load R&D. Shoots in .3's consistently barring wind. .22 Hornet my all time favorite groundhog rifle hunting in orchards in PA
Primer choice matters with the Hornet. With such small charges of powder, you want a mild primer. I had best results from the Remington 6 1/2 primer, which are in stock at several online retailers. Powders...I use 10 grains of H110 with the Hornady 45 grain bullet, which runs about 2600 fps in my rifle. I bought an 8 pound jug of H110 a decade ago just for my Hornet, still got a long way to go...you get a lot of loads from a pound of powder with the Hornet.🙂