I've always wondered if the grenade launcher could be more viable if it's projectile can go through enemies, specifically the common infected. I've done some testing with other projectiles, and I found out that pipe bombs and molotovs can go through enemies. This makes sense since they are meant to clear out hordes/ crowd control. For grenade launcher, you have to aim over the first common if you want to clear out hordes effectively.

I'm not sure if something like this is possible, like, is the grenade launcher's projectile collision hard coded or do all enemies share the same collision for projectiles? Does changing the projectile of the grenade launcher also effect other weapons?