I have a Ruger 77/22 Hornet VHZ. My best load so far is 12.7 Grs Lil' Gun with a 35 Gr Hornady V-Max bullet. I use winchester brass. For me CCI standard small pistol primers and the Winchester standard small pistol primers seem to be interchangeable with this load with no effect on accuracy. The worts 5 shot groups I have gotten with this load were slightly under an inch at 100 yds. most 5 shot groups range from 0.50" to 0.75". Yesterday I shot my personal best group ever-a 5 shot 100 yard group that measured 0.236". The man I bought the rifle from had installed a spring and sear kit so it has a very nice trigger pull, nothing like Ruger's standard "Lawyer trigger."
This rifle consistently outshoots the .222 Remington T/C Contender Carbine that I traded for it, plus it is much cheaper to load for. I am one happy man, and I have not been a big fan of Ruger rifles in the past.
I hope you get as much satisfaction from your hornet as I have been getting.
Scott.