The era of the old round-nose was coming to an end by the time I put on a Sam Browne; we had that fancy Super Vel 110-grain ammo. But we still shot a lot of lead ammunition because it was cheaper.
For a gun that is celebrating its 110th birthday this year, the Model 10 is a fine gun and I wouldn't have any problem with it. A little polishing of the innards and the Model 10 is a sweet-shooting gun. I used to have a Model 10 with the old five-inch tapered barrel and a buddy of mine had the six-inch barrel. Then we both got the four-inch bull barrel version and I have no idea how many rounds of .38 Special we put through them.
We had a three-station RCBS reloading setup and could really crank out the reloads. Bought cast bullets from a fellow in San Antonio. I remember one time, my buddy called me and told me we had to go up to his ranch and burn a thousand rounds because he had forgotten to wipe the beeswax off the bullet bases and we needed to use them up before the wax contaminated the powder. We each fired off 500 rounds through those Model 10s that day.
Everyone bellyaching about the ammo is apparently unfamiliar with the term "issued ammunition." What was in your gun and on your belt was what the department said was going to be there or you were going to enjoy an unpaid vacation. 158-grain RN was "issue ammunition" for a lot of years. If you were serious about coming out on top, you spent a lot of time at the range.
I don't have a Model 10, mostly because I haven't been able to find one, but I do have a Model 60 with a three-inch barrel and I actually have a couple boxes of 158-grain round-nose lead cartridges. They're range fodder and I sure as heck don't plan to use them as SD ammo but if that was my issue ammo, I'd make the best of it. After all, it could have been worse; we could have been stuck with Iver Johnson Owlheads in .38 S&W!