I bought one of these in 1997 as my first CO2 pistol. Each chamber in the cylinder had a different point of aim. It was very plasticky. I really did persevere with it, but to no avail. I ended up getting a CP88 which was a better gun. I guess that they may have improved the pistol, or I may simply have had a lemon.
I was very pleased with the CP88, but now have a S&W 586 4", 6" and 8" revolver set, which satisfies that revolver urge, whilst being accurate and powerful enough for fun plinking at spinners, re-setters, old 12b shells, extra strong mints and beer cans. I'd guess that you could get a s/h S&W 6" or 4" from the sales section on here, for the price of a new R77.