Black locust bows last forever when used as little skinny fence posts. Black locust is springy but more susceptible to failure than hickory.
Properties of wood that matter in different applications:
Availability
Weight
Hardness
Rot resistance
Rot resistance in water or soil
Workability
Dimensional stability with moisture variation
"Beauty"
Resistance to splitting or ease of splitting
Impact resistance
Strength with or across the grain
Springiness
I am sure there are others.
For gun stock woods, strength with and across the grain, workability, availability, stability with moisture variation, impact resistance and beauty leave us with the top 3: medium to hard maple, walnut, cherry, with ash and a few others acceptable to our forefathers
Black locust is great for fence posts, sill logs, tool handles, and good for bows. Osage orange is good for much the same.
Hickory makes the most reliable bows (least likely to blow up) but sucks up moisture. Nonetheless, northeastern Native Americans preferred it for bows. Hickory really doesn't care if the grain is "violated" on the back of the bow but great care must be taken with Osage and black locust.
I prefer black locust for bows because I get it for free and it can make a very powerful bow. Some of them have failed early in the tillering process, though.