You know I thought about this too, my take was it's a feat, if your accuracy to the target is very high (exceeding 100%) then the amount of extra precision is multiplied by a certain factor, and used as the chance for you to penetrate the main target and deal damage to the target behind it, it could be interesting.
I've been shilling this 'excess precision' mechanic before because it provides you with some reason to use bipods and scopes, instead of forgetting about them completely once you have access to advanced scopes and smart modules.
Kind of a slim chance of it getting added though, since sniper rifles are already very powerful.