Works exactly as claimed on my rifle - Geissele AR-15 Super 42 Buffer Spring/Buffer Combo For Carbine Receiver Extensions

This spring/buffer silenced the twang in my rifle and cycles perfectly. Here are the details of my setup in case you are trying to get the same result:

16" lightweight barrel with Wylde chamber
mid length gas tube
carbine length Aero Precision receiver extension (buffer tube)
.078 (5/64) gas port
normal hammer spring
nickel-boron coated bolt

Functioned well with no issues with various brands of 55-62 grain commercial .223 and 5.56 (including ss109 and xm193), as well as light, moderate and maximum handloads with common powders (Varget, Benchmark, 748).