I know that data is available for the use of 4f as the main charge in handguns. I use only 3f in my handguns but that is because all of my handguns are .44 caliber and larger. My largest handgun caliber is a sweet .54 single shot flintlock. I just don't feel safe using 4f in anything that large. I won't say that you can't use 4f in them, I will just say that I choose not to. On the other hand, I use 3f in all of my rifles from my .36 up to and including my .54 caliber rifles. They all peform quite well with 3f. In fact, 3f is the only powder that I buy. I do have one can of 4f and one of Null B and I use them as priming powder. I think that I have enough of those two powders to last the rest of my life and to pass some along to my heirs.
4f in pistols? Well, there is enough evidence to say that 4f makes a good pistol powder but will I use it? Nope, I have enough 3f to last a long long time and I find that it works quite well in both my handgund and in all my rifles. I'll reserve my 4f and/or Null B for use in my pans. I'm not advocating that for everyone, it's just what I do. :hatsoff: