"+P" designation. Others point out that +P ammunition is the same pressure as the regular pressure ammunition was before SAAMI lowered the standards in 1972 as a result of industry requests. They point out that the post-'72 loads are merely regular pressure ammunition labeled as "+P". Some experts have done considerable testing so as to prove that +P .38 specials are not truly hot loads. In the owners' manual accompanying some post-1972 Cobra revolvers, Colt recommended the use of +P ammunition for 2nd Model Cobra frames only, with the stipulation that the gun be returned to the factory for inspection every 1,000 rounds (compared with a 2,000–3,000 round interval for the 2nd Model steel-framed Detective Special). The new 2017 reintroduction Colt Cobra revolver is rated to accept +P ammunition. The Cobra should never be fired with extreme-pressure +P+ ammunition as there are no industry standards for such loads. Notable users Official gun of Atlanta Police Department. Jack Ruby used a Colt Cobra .38 to kill Lee Harvey Oswald on November 24, 1963 as Dallas, Texas law enforcement officials were transporting Oswald from the city jail to the county jail. The infamous gun was purchased for $220,000 at an auction held by Herman Darvick Autograph Auctions in New York City on December 26, 1991 by collector Anthony V. Pugliese III of Delray Beach, Florida. It was consigned by Jack Ruby's brother, Earl Ruby. Lee Marvin carried two Colt Cobras while playing Detective-Lieutenant Frank Balinger of the Chicago Police Department on the TV series M Squad. Monika Ertl used a Colt Cobra .38 to kill Roberto Quintanilla, the man who cut off the hands of the corpse of Che Guevara, in 1971. Legendary music producer Phil Spector was convicted of murdering actress Lana Clarkson with a Colt Cobra .38 at his Alhambra, California home in 2003. The Colt Cobra was the favourite weapon of Michele Cavataio, in fact he used this weapon into the first mafia war. Ray Midge, the protagonist of The Dog of the South by Charles Portis, has this gun confiscated by a border agent while trying to smuggle it from Mexico into Belize in a lemon pie box. References External links The Colt Revolver in the American West – Experimental Cobra Model The Colt Revolver in the American West – Aircrewman Model guncollectorsclub.com on the .38 Special version Ballistics By The Inch tests of the .38 Special cartridge.