The S&B case will fit in a #2A shell holder (rather than the standard #2 for other 7x57/.275 Rigby cases)I use S&B 7x57 brass for my Ruger 275 Rigby. The factory rounds in 140 gr shoot quite well. The brass however is a bit out of spec. The head, for example won’t fit in RCBS shell holder. Plus the brass case head is a bit thinner than REM. Or Win. Brass. When I re-prime using my Lee priming tool, the primers don’t quite fit just a bit below the case head as they should. Instead, they seat a bit proud and require a run through my old RCBS primer to seat fully just a bit below the case head.