I have these two 5.5" Bisley's, the 45 and 41 are real thumpers and extremely accurate loaded with my heavy cast bullets. Been around Rugers a long time however never heard of a stock Bisley with aluminum frame.
My one and only dislike is the Bisley grip contour that isn't kind if you have Sasquatch hands and fingers negating a change of hold vs the more comfortable conventional plow handle contour..
The weight of each 50.4 and 46.8 ounces is a necessity IMO especially since I primarily load the heavy end of the spectrum.
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This hold is a knuckle buster so I slide the pinky finger down a notch.