For my 1851 Navy, Uberti says # 11, but these are to loose, # 10 are too tight, RWS 1075 are just right, but at a price of $5.00/100... so I just squeeze #11's (I tried CCI and Remington).
For my 1858 Remington, # 11 is just right!
BOTH ARE UBERTI'S!
Yes, I'm a squeezer.