Klik,
Got my 1B in 2003 and it's always been one of my most accurate mid-range varmint rifles. Ruger started hammer-forging their own barrels in the early 1990's, and while consistency improved immediately, hammer-forging does take some practice, and after a few years the barrels started getting really good.
If I use benchrest-style handloading techniques mine will put five 40-grain plastic-tips well under 1/2" at 100 yards, and 10-shot groups with about any 40-grain will go under an inch, and depending on the load 3/4". Cast-bullet loads run about like yours--except mine are from a 44-grain Lyman gas-check mold. Tried several variations and it turned out the best accuracy was with unsized bullets without gas-checks, lubed with Alox, and 5744 with CCI 500's. With jacketed bullets and a case full of Li'l Gun or Alliant 300-MP, CCI 450's work best.
I used to have a wide selection of No. 1's. The Hornet is the last one left, but ain't planning on selling it anytime soon.
