Fallout 4 Rifleman Build
Truely a stat dump build, the rifleman build dumps your remaining stats into PER to get Concentrated Fire (arguably the most consistent 10 point perk, but isn't all that useful until level 50).
Starting stats should be 2-6-2-5-5-6-2. 2 luck opens up Bloody Mess after picking up the bobblehead so you don't waste a bobblehead. You'll need to spend 2 perks to get PER to 10 with the You Are Special book and the bobblehead very early.
Core Perks (40 levels)
Armorer 4, Rifleman 5, Locksmith 3, Concentrated Fire 3, Life Giver 3, Caps Collector 2, Local Leader 2, Medic 1, Gun Nut 1, Hacker 3, Science! 1, Action Boy 2, Ninja 3, Bloody Mess 3, Perception Training 2, Penetrator 2
Quality of life perk for VATS. Since the build invests a lot of perks into VATS stats, this is a good option considering it's only two points.
Optional perks and beyond
With 10 additional perks at level 50, there are three of different routes you can take. Each path will spend points until roughly level 60.
Stealth/sniper path (14 points)
The stealth path can also steal the Gun Fu idea from the versatile build path but benefits a little less from the perk as sneak attacks won't carry over.
Ninja was originally part of the core build but this perk doesn't offer enough value to warrant inclusion (an unbuffed 2x sneak attack is enough).
Five points to make your sneak attacks more consistent is worth it. Reengaging stealth to get another sneak attack almost bumps this perk into the required category but ultimately cost a little too much.
Three perks and adding a suppressor to your weapon for 50% more damage is worth it. One drawback is that it slightly pigeonholes you using ballistic rifles over energy rifles.
I don't really like the sniper perk all that much until the accuracy boost at level 26 and I'd probably even prioritize Penetrator over the Sniper perk, but since this perk should be mentioned and it makes sense most if you decide to snipe.
Agility training is pretty much the defintion of value proposition. Since the build is so close to the bottom of the agility tree, the question is "Why not?"
Gun Fu is a situational perk that makes fighting groups of enemies much easier. This perk is very situational, but you can normally plan your attack by creating a choke point to get more value from this perk.
Get to 6.
Better Crits allows you to make your opening attack even stronger. Criting a sneak attack for 250% more damage is pretty awesome.
The following perks don't apply strictly to any of the particular paths mentioned above but offer some sort of quality of life improvements to the build.
Lumping these two perks together, not a bad thing to finish off these perks because it makes upgrading weapons a lot easier (no more shopping) and gives you a few more advanced options in settlement building.