Jim my 45 caliber dual diameter shoots very well to 1000. It's also from Brooks and it's a nose pour adjustable with his original postel nose. I just wish I would of had him make a flat base plug for it during the build.
My first dual diameter bullet came about 10 years ago from Bernie at Old West, he said he copied it from a bullet pulled from a factory loaded 45xxx round. It was .435 on the base and while if you wrapped it in pretty heavy paper it would shoot ok to 300 yards or so. I used it to take an elk or two and some antelope, but sort of set it back , until I got the first 44 -77. Wrapped in 8 or 9 lb paper that bullet shoots very well in the 44-77's, and both 44-90 straights.
I did some checking on the 40 caliber bullet this evening. Cast from 16-1 it measures 400 on the base and 395 at the base of the nose. Wrapped in 7 lb paper it fits about right in the mouth of a fired 40-90 case.. Now I got the itch to cast about 100 of those and take with me to Phoenix...But that 10 lb rifle wears on me pretty hard during a match.
A wise man can always be found alone. A weak man can always be found in a crowd.