In PUBG (PlayerUnknown’s BattleGrounds) Kar98 and M24 both are the most popular sniper rifles which have the highest damage after AWM the most powerful sniper.
Thinking of any serious advantage of choosing one over another, I’d say always prefer M24 or use Kar98 unless you find M24. Both the snipers are capable of penetrating level 2 helmet from any distance, but M24 can penetrate level 3 helmet if the target is under 300 meters, that’s why M24 is a better sniper rifle in PUBG.
Bullet travel of M24 is slightly higher than Kar98. Similarly, the initial bullet fall velocity of M24 is lower than Kar98 while the firing rate of both is the same.
Kar98 is easier to spot where M24 rarely seen or found mostly in hot areas. This doesn’t mean that Kar98 sniper worst but the second better option after M24.