Analyses have been made at USNTDL with a singie-chennwl amm@-ray spectrometer, of radiation emitted by 21 selected radicactive fallout samcles collected by Project 2.6.3 at the Spring, 1956, weapons test series known as Cperation REDWING at the Pacific Proving Grounds. These measure- ments were made to determine the spectrometric characteristics of the fallout radiationversus time and to compare these characteristics for consistency among samples from the same and different shots. The present work is a continuation of the spectrometric analyses of fallout gamma radiation which have been made at Operation UPSHOT-KNOTHOL=2 at the Nevada Test Site in 1953, <x Operation CASTLE at the Pacific Proving Grounds in 1954°, and Operation TEAPCT at the Nevada Test Site in 1955 3°", taking advantage of further refinements in instrumentation and analyzing technique, Project 2.6.3 collected samples of various types at several ship, barge and land stations and returned them to NADL by air. This rapid return allowei analysis to begin as early as 51 hours after shot time--a notable im~ provement over the earliest-time receipt of 4 days accom-~ plished at Operation CASTLE, Other samples requiring specialized handling, i.e. welxshing, aliquoting, evaporation, 1