I'm confused about the various frames on Ruger single actions. I have a New Model Blackhawk .45 Convertible serial number 48-xxxxx. Will this gun handle Ruger only loads?
Yes, your BH will handle “for Ruger only reloads.” To date all mid-frames have 3 digit serial number prefixes. A .45 BH with a 2 number prefix has a large frame.
You can also identify the frame size of a .45 BH by the sights. Mid-frame .45s are all flat tops with Micro sights. Large frame .45 BHs all have Ruger’s traditional adjustable sight set down in between the raised sides of the rear of the top strap.
There’s no telling what the next custom order by a distributor might be but for now those two identifiers work for adjustable sighted .45s.
The 45s on the mid size frames, the New Vaquero and Flat Top BH, will even handle tier II 45 loads, but not recommended for tier III "Ruger only loads".