When someone asks me to chronograph their load I usually give them a hard time before I do it. I'm sure there's an excuse I haven't heard but I always ask the supplicant why he doesn't have one of his own. The litany runs: "too expensive, too much trouble, I don't know how, you can't use them inside" all the way up to "the dog ate my homework." All are bogus. You can buy a wonderfully convenient chronograph for well under $100, or a very elegant one for less than the average cost of a gun and, with proper lighting, work fine indoors.
Trouble? Hardly. I own several different chronographs, but when I want to measure a small sample the one I use is the Shooting Chrony. All you have to do is put it on a tripod and shoot. If there's anything simpler it would have to be some psychic who knew just by holding a round--which probably happens. There was a time when people scoffed at the Chrony as being too cheap, but the fact is you get the same number from it as you do from one costing many times more.
Chronographs are terribly misunderstood gadgets. In our world, if Johnny has three apples everyone can see and agree. But then along comes a curmudgeon who says he sees four, so now we have to think a bit. Well that's kinda how it is with velocities. If you chronograph five rounds the only certainty is you will not get the same number even twice. So for velocities we deal with averages. We must, because gunpowder--even if weighed to the nearest militad--does not produce exactly the same amount of gas each time, bullets can vary in weight by a few tenths of a grain, the sun may be shining or maybe there's a low pressure front coming through. Those, and a host of other variables, torment us with a lack of precision making it prudent for us to take velocities with a pinch of salt. They're easy to get, but easy to misjudge as well.