Ah, the 45 and Silhouettes - what a combination. The Silhouette converted me from being a dyed-in-the-wool .22" user to .177", and all due to Dave Welham recommending I try Silhouette.
I shot that 45 even after it seemed everybody else had switched to the HW77 and believe that, accuracy wise, it was a match. If anything, the 45 seemed to give very good accuracy with a wider ranger of pellets than the 77.
I'm not sure what pellets my friend is using through it now. Whatever pellet he is using must suit the 45 or I'd have heard about it.