My issued weapon was a M10 RB with the heavy barrel, There were several different wheelguns in the arms room; the above mentioned pencil barrels, a couple of Colt 38s, even a couple of Colt Detective Specials. I took my HB with me when my unit was colocated with the USAF at Ubon in Thailand. There the AF guys had M15s, some of which had 2 inch barrels. The armorer there did an action job on my M10 HB that is still the best I have ever had. I was a kid then and foolishly turned it in when I processed out of country, when I think of how many ways I could have "lost" it, I get sick even today. I am sure someone with more experience than I had now owns that gun.
All of the guns were pretty much off the shelf blue models. Looked like the Army just went to a gun shop and bought them. There were a couple of older revolvers that seemed to be parked. Some were marked US property or some such, but many were not.
I still have the Colt M1908 in .380 that my Dad carried through WWI and WWII. He bought it in 1913 when as a very young merchant marine officer he knew he was going to be called up(he was Canadian). He bought the gun in Boston, MA. Just went into a gun shop and bought the gun and 200 rounds of ammo and walked out with the stuff, try that today in MA!
He carried that gun all through the war on a Royal Canadian Navy Cruiser which was assigned to the African theater. He carried it ashore with a boarding party to attack a German Light Cruiser up some river in German West Africa, got into a fight with a German officer who tried to use his sword-really, brought a sword to a gunfight. Dad blocked a swing with the gun then shot the German and took him prisoner back to his ship. They became friends and corresponded between wars while each served a merchant marine officers. Come WWII and Dad got called up again (he had become a US citizen and joined the USNR), and packed the same gun, along with a Colt snub .38 special he acquired in 1930 all during WWII. Never used it except for shooting off the deck of the carrier he was assigned to. I inherited the guns when Dad passed away in the 70s. Both were somewhat the worse for the wear so I sent them to Colt to be refinshed, however dad had made me promise never to repair the gash on the trigger guard of the .380 which the German sword had inflicted. Still got them both. After WWII Dad and the German officer met again, still as merchant marine officers. In 1960 the German came to the US to visit Dad, and in 1964 when I was assigned to Frankfurt as an Army pilot I stayed with him and his family for a while. He passed away in 1982.
Every now and them I take out the guns and clean them, oil them up and put them away. For a while I even carried either of them as an off duty weapon, they both shot well, and carried nicely. I am saving them for my grandchildren via their parents, although not too soon I hope.