Welcome to My Guide
Howdy, it's me again! StormTail22 of the WFGuild! None of y'all will really know my clan, still it's just something to mention. I'm a warlord of my clan, though I primarily play on my own, I'm sharing the builds I use or design myself! Today is, well the [Kuva Chakkhurr], my favorite rifle.

Quick Description
Can't rightly get into the explaining what my choices for it are without telling y'all about my favorite gun. The [Kuva Chakkhurr] is a nemesis weapon that came straight from the forges of the Worm Queen, a first gen kuva tech weapon. You can only get it from killing a Kuva Lich, this means you have a special bonus element on top of this delightful weapon's damage. It is a flintlock style rifle, although it fires far more than only once before reloading, it still feels like hitting a fool with a golf ball sized round. The rifle is very much a sniper in feeling, even with an explosive shot to say "f you and everyone 2.9 meters near you!" and at a only 30% damage fall off in the aoe, it's only good being about 3 meters away fully. The reload speed is slow but the power of doming an enemy is worth the slowness of this gun, dealing a bonus 50% headshot damage. Crit chance and damage are some of the best in class of a semi auto rifle. It ain't a sniper but it does use that ammo pool.

Head Eraser
So, I personally use this to practically erase the heads of anything unlucky enough to be in my line of sight. It ain't only good for that but it is the best thing it does, since it is a burst type of weapon, I recommend aiming for the face! I use this primarily on the tougher enemies that stand a good chance of withstanding my side arm or even risky hitting with melee, so mostly just the Kuva Lich and Sister of Parvos. That explains a little of my mindset hopefully which brings me into why in the ever loving heck I made it this way. The elements are entirely arbitrary, I just happened to make a toxin one when I got my chakkhurr, I used radiation as the modding element just because I fought primarily grineer enemies and it made stuff fight each other. I have a corrosive set up made to counter mostly sentients, along with it being a once steel path build until I made that viral (most likely a mistake but I don't do steel path often). I won't take some large rambling part about what can be changed for what, it is a personal choice matter but I use radiation.

The choice of crit and multishot focus is for two thing: this weapon is a freaking beast with crits, making headshots even better too, thus it only seems right to use a rifle like this as a crit weapon rather than a hybrid ([Hammer Shot] is for the crit damage btw). The multishot is more for the same reason most primaries are good for it, they are designed to fire a single shot which makes the single shot powerful so it makes any multishot turn it into a more painful threat, something I learned more from Eidolon hunting in the past. So, those are why I used that stuff to build this weapon, I didn't care for fire rate much when the damage did the job well enough anyways. Ammo mutation is because of how rare sniper ammo is anyways, I don't like avoiding entirely using my primary for a mission.

TLDR
~ Elemental damage is a personal choice, fit it to your intended foe
~ Critical damage and chance are incredibly useful on this psuedo sniper, making a headshot even more useful
~ Multishot makes single shot weapons really strong
~ Ammo mutation is because sniper ammo is rare
~ Treat it like a sniper

Closing Remarks
Overall, this is just a build I have optimized for my particular tastes and uses. I like making a weapon erase an enemy like Kamui! This is great for hunting big game but that's it. This build may not be perfect for you, it packs a punch still. I am not a perfect modder, though I am using the tools this site has, if you have any thoughts or criticism about it, please leave a comment. I hope you enjoy my weapon of choice, may it serve you well!