My Ruger likes 12.6-12.8 gr Lil Gun, CCI Small pistol primers, and a light to moderate crimp with the lee factory crimp die. I either use the 35 or 40 Vmax seated to magazine lenght and get sub 1/2 groups at about 2900 fps. I haven't experienced any extreme velocity spreads as mentioned, since I started crimping and using small pistol primers. My ES and SD's are very low now.
The 35 vmax shoots great and works on foxes and groundhogs, but past 100 yards it drops like a brick. The pointier 40 grain bullet flies true past 200 yards with ease. I have been told the 40 vmax may splash on coyotes, and I should try the 40 gr Sierra Blitz Kings or Nosler B-tips for tougher construction, but I don't plan on using the hornet for coyotes and haven't loaded any yet.