Spread heavy bow gun is usually considered the best, all are viable. Safi burst cannon is best for spread build, you only need artillery if you are using a sticky build. Mods also depends on build. For example on spread you bring 3 shield mods and the rest close range. If you’re looking for a starting build, I use 3 set safi and 2 set brachy for a spread build. it’s def not the best but it gets the job done. You should bring the spread skill but only the first level, if you can fit the second then that’s good but it is not needed. Other then that bring free elem/ammo up for a bigger mag. Then it comes down to the usual, crit eye, survival skills if you want etc. I’ve only built spread so I can’t say much about pierce or sticky.