Daryl / Lancaster,

I have just deleted a posting about using a 148gr 9mm in a cut off 223 case to make a .375" bullet. I slept on it overnight and the more I thought about it the less I liked it. I did some more measurements this morning and I couldn't be sure that I hadn't got an airspace in the base of the case around the bottom of the bullet. That didn't sound like a good thing so I abandoned that idea and went back to the drawing board.

I think MkII is much closer to what you've been talking about. I cut off a 223 case just below the neck and pushed a 200 gr .30" cast bullet into it nose first. I then applied the blow torch until the lead melted. Once it had cooled I trued up the case on the case trimmer and took some measurements. The whole bullet is just over 1" long. The case still has its taper on it but as you said the base is .375" for about 3/8". For good measure I ran the whole thing as far as it would go up into a 38 Super crimp die and this reduced the first 1/4" to .360" in diameter.

What I now have is a .375" bullet with a wad cutter nose.