Most current 44-40 rifles from Uberti are running .429, but my '73, which was made in the 1980s is .427. At present I own five rifles chambered for 44-40, some are .427, some are .429. I have compromised on .428 as my bullet diameter. I use the Big Lube Mav-Dutchman bullet sized to .428 and lubed with SPG in all my 44-40 rifles now. Yes, 2.2CC of FFg is what I use. It compresses about 1/16" to 1/8" when the bullet is seated.