No newer Revolvers made for the 38 S&W cartridge that I'm aware of, it originally came about over 145 years ago. There were revolvers made for that cartridge by Colt, Iver Johnson, and Smith & Wesson, I believe as late as the 1960's.
So your friend can either buy one of those (for instance Colt Police Positive) that was chambered for the 38 S&W if he wanted, or he could sell the ammo. There is still demand for the 38 S&W cartridge by people who have older revolvers in their collections. Before Covid hit, it was being manufactured again by a couple of manufacturers because of that demand. But like other cartridges, its become hard to find again.
I have an almost 140 year old Smith & Wesson 3rd Model Double Action that my Dad passed down to me a couple of years before he died, It was made in 1886 and chambered in 38 S&W. Its a top break revolver, and because of the latching mechanism, that latching mechanism is its known weakness.
Fortunately it hasn't been a problem with this one, and I dont shoot it either. But my Dad use to shoot it and I shot it with him a couple of different times over the years. It's been in the family and passed down from generation to generation, and it has endured the test of time.
Because they made so many of them, its not worth a whole lot. But the value of it to me goes deeper than monetary. Here's a pic of the 3rd Model Double Action. I also collect Morgan silver dollars of the same time period, so I included a few of them as props in the photo.