I stumbled across this very cool personal story blog about a guy that was a Sky Marshal in the early 1970's for about 2 years here at http://skymarshalstory.blogspot.com/2007/11/how-it-all-started.html.
The writer talks about some of his experiences as a Sky Marshal when that program was first conceived here in the US in the early 70's. Of course, the program faded away until the tragedy of 9-11 and the Air Marshal's were once again placed on airflights to keep us, the flying public safe.
One misconception I had was that the 1970's Sky Marshal's used Charter Arms Bulldog model pistol in .44 special caliber. I have not read far enough into this cool blog to see if there was a changeover while he was flying the unfriendly skies, but the gun he used was a S&W snubbie with special ammo that he talks about on his blog. I do seem to recall reading somewhere "back in the day" that Sky Marshal's had selected the Bulldog because of it's bigger, slower bullet, thus lessening the chance of overpenetration of the target into another person or the airplane covering.
UPDATE: I did do some further searching and the only mention that I could ever find on the "internets" were some gun forum posts posing the same question, i.e. whether the "Sky Marshal's" in the 1970's ever used the Bulldog as an issue weapon. All of the chatter seemed to support that they were issued Smith and Wesson revolvers in .38 special caliber.
The Sky Marshal blogger says that after completing the Sky Marshal academy, that the Sky Marshal's were encouraged to pick a back-up weapon, with the implication being that in foreign countries where their weapons had to be surrendered upon landing, that the agent only surrender his duty weapon and surreptitiously carry the back-up weapon "in country" on their off duty jaunts.
In any event, I've read a few of the posts and plan to keep reading.
NEW for 2018: Hornady Rotary Case Tumbler
7 hours ago