The guns pictured in the post above, with Bienville Parish Deputy Sheriff A. B. Rogers(not one of the Officers who shot B&C) were recovered from the death car in Louisiana on May 23 1934.
The guns in the auction in the news were supposed to have been recovered after a Barrow gang shootout in Joplin, Missouri April 13, 1933 that left Joplin PD Detective Harry McGinnis, 53 and Newton County Constable J.W. Harriman, 41 dead.
When the Barrows fled their Apartment they left several weapons behind, and an undeveloped roll of film that showed various gang members posing with weapons including a Smith & Wesson Triple Lock .44 special wearing jigged bone grips that they had taken from Springfield Missouri Motor Officer Thomas Persell when they kidnapped him January 26 1933, and took him on a joy ride.
After the shootout between the Barrows and authorities in Iowa at Dexfield Park on July 24 1933 a bushel basket of Colt 1911s was recovered from their car.
Also recovered was a S&W M&P .38 Special, SN#335772, that had been taken from the body of City Marshal H. D. Humphrey of Alma, Arkansas who was killed in a June 1933 shootout with members of the gang on U.S. Highway 71. The gun was in possession of the Alma PD up until a few years ago.
As Joe said the bulk of documented Barrow guns are in the Texas Ranger Hall of Fame Museum in Waco Texas. A place anyone who enjoys firearms and history must visit if they are anywhere close.