My 2 cents on burst-fire guns in ME3MP:
1. Valkyrie
This rifle is a beast, higher damage per bullet than the Harrier, coupled with 3x headshot multiplier, easily among the top 5 ARs for me. Some console players may say they cannot deal with the recoil, but it's fairly accurate and easy to score headshots especially on PC.
Kits: any kit that boosts stability/RoF/accuracy can make good use of this gun, such as Turians, GI/GE and Destroyer.
Mods & ammo: For non-infiltrators, use extended barrel and mag(for AP/Drill rounds), or piercing barrel/mod and mag(for Warp rounds). For Infiltrators you may want to drop mag and replace it with other mod (like stability damper), less magazine for a better pace (cloak->shoot->cloak to RC) so TC buffs more shots.
2. Argus
Decent rifle, high damage and heavy recoil, not versatile as the Valkyrie, but fun to use anyway.
Kits: very limited due to the recoil, it's best to use it on TGI/Tsol.
Mods & ammo: Scope/stability damper for TGI, better to use it like a sniper rifle and avoid close encounters. Stability damper/mag on Tsol. Always use AP/Drill rounds as there are no other choices.
3. Hornet
Decent pistol, dps is good but reserve ammo is too low. Some tips: shoot at close range and never zoom in, the recoil will become sky high if you aim down the sights.
Kits: Adepts/engineers that have CC/stagger powers, if you just want to complete the weapon's challenge, use it on GI.
Mods & ammo: Recoil system and HV barrel, Warp rounds for Adepts and Incendiary rounds for Engineers. High caliber barrel and recoil system (with AP/Drill rounds) for weapon kits.
4. Incisor
Not a great weapon, but has potential due to its decent dps, not recommended for most kits though.
Kits: Contrary to most other sniper rifles, this gun performs better on TGI/Tsent than on GI due to the gun's wild recoil.
Mods & ammo: Spare ammo and extended barrel with AP/Drill rounds, or spare ammo and HV barrel with Warp rounds, just don't forget to equip stabilization module III to make the most of the gun's dps.
5. Shuriken & Vindicator
These 2 guns were good/decent back in ME2, but in ME3 they just suck, so don't bother until you really want to complete the weapon challenges, again, use stability boost kits/mods/equipments to more or less ease the guns' annoyance.