I'm starting to load some rounds for a Ruger 44 carbine rifle. I'm using 240gr hollow points, these are Hornady XTP's. The powder will be H110. I always cross check data in different manuals to see where I want to start. Hornady specs a Large pistol primer with H110. Speer specs a Magnum pistol primer with H110. Hodgdon specs a Large pistol primer with H110. I have both CCI 300's and CCI 350's. Why would Speer use Magnum primers when Hodgdon and Hornady use Large pistol?? I think I'll probably end up somewhere around 23gr or 23.5gr of H110 to achieve around 1700fps based on the data I have. Does it matter that much which primer I use??