I don't have one but a decently rolled "Her Benevolence" is proven to be the top Sniper for Trials. It has the highest base Aim Assist. If you roll Shortgaze Scope and Hidden Hand this further enhances the Aim Assist and it can 1 shot through Revive + Self Revive shield. Here is a very comprehensive guide on Reddit. https://www.reddit.com/r/DestinyTheGame/comments/37gpws/sniper_rifle_and_reforging_tier_list_for_pvp