It would seem Sig has redefined the ABC engine. Their "true ABC construction" has a "steel alloy" cylinder and I always thought it was chrome plated brass oh well live and learn.

Still for the price it might be worth investigating.
Andy
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For instance, the connecting rods use the same aluminum alloy as found in some full size aircraft engines. Crankshafts are one piece hardened Cr steel. A specially developed "KK" bronze alloy is used for the conrod bushing which allows it to withstand high RPMs. Cylinders are made of a special heat treated Cr
steel alloy to insure a hard and true cylinder that will not distort at high temperatures. Piston rings (1.2 - 2.0 in3 engines) are made of the same steel alloy as found in some racing motorcycles. The .46 in3 is
true ABC construction. All engines contain high quality dual ball bearings.
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