Originally Posted by Mike Rowe
The correct bullet diameter for the 450 BPE is .450. Wrap it with 11 to 16 lb paper and you'll be fine.
The original Kynoch and Eley bullets are this diameter, and the Kynoch factory drawings show a 1 in 12 alloy. Make sure you use only a lead/tin alloy, or the bullets will not obturate correctly.
They seem to work fine in any bore configuration I've tried, remember, a good double 450 is a 3-4" grouper at 100 yards. Plenty good for hunting.

Thanks Mike for your valued response.