You're suggesting the thing fires all 4 barrels in 1 shot
Kinda feel like making a more burst damage intensive scattergun than the force a nature will be annoying on the receiving end and make the force a nature a less preferable option

This should have its own niche

Perhaps -15% speed on wearer

I think you should have the ability to choose between firing each barrel separately or firing them off all at once, kind of like a double trigger. However, with each mode, you can pick between slightly less damage with greater range or a huge burst of damage right up close. The reload penalty should be there as well.

Oh, and give the alt-fire of all four barrels the Doom 2 super shotgun sound.

+30% Damage Increase
+20% Primary Ammo Capacity on Wear
+Causes 4 Seconds of Bleed

- Fires all 4 Rounds in one shot.
- Marked for Death upon reload for 5 Seconds.
- +30% Damage from Melee Attacks
- Can only Mini-Crit. (Random Crits become Random Mini-Crits.)

Shots cause a small amount of knockback and halfs targets speed by 1.5 a second , -20% accuracy , +30% more bullets , -10% less damage , +300% more testosterone

The Prime Finisher

Shinzo Abe approved

I'm a little worried this might be abused in conjunction with the crit-o cola and would be perhaps a bit less appealing to use in servers that disable random crits, but I guess if the server disabled random pellet spread it would make up for that

Other than that, seems fairly solid, I'm not good at scout but I could see this being a very fun, high risk high reward scatter gun

50%+ more accuracy
50% more damage
60%- less bullets
- damage falloff is reversed(the closer you are to the enemy you deal less damage but if u are far enough you'll deal the base damage
-70% less reload time
reloads it's entire clip at once
- no random crits

I had an idea that htis weapon could perhaps be a mini sniper rifle for the Scout

Left Click to fire 1 Shell, Right Click to fire All Remaining Shells in the chamber
+Slightly Increased Firing Speed
+10% damage for each shell in a Volley 2 or Above
+25% Knockback for each shell in a Volley 2 or Above
-50% Increase to Spread for each shell in a Volley 2 or Above
-10% Damage Dealt
-15% Reload Speed
-33% Clip Size

Basically, you can Kinda use it like a Scattergun, with the Risk Reward of "If you're like Right Behind a heavy you can 1 shot him and leave yourself with No Ammo"

+one hit kills enemies using weapons from the Shogun Pack (Half-Zatoichi, Fan O'War, Concheror, Conniver's Kunai)

I could see something along the lines like:

= All four shells are fired on a single mouse press click in a rapid consecutive fashion.
= Damage increases after every shot while accuracy decreases after every shot
+ All landed pellets cause -2% slower movement on target
+ All landed pellets cause additive knockback
- 10% less pellets per shell
- 33% clip size

something like
+ 15% damage
+ 20% reload speed
- 33% clip size
- 20% accuracy
-40% reload speed after using alt fire for 5 seconds
alt fire to fire all 4 shots at once dealing 4x damage
this weapon reloads its entire clip at once

Since it looks like demoman's launcher, there goes my suggestion: fires slugs with proximity detonation fuse. Basically it fires projectiles (like demoman's pipes but with faster initial speed) and when these projectiles are close to enemy they replicate a single scattergun shot in enemy's direction dealing up to 100 maximum damage or so. Detonation has a small delay so you're able to reduce taken damage by dodging. The damage falls off with slug's traveled distance but it still does more damage at medium range than other scout's guns. The shooting and reloading speed are comparable to demoman's launcher as well. Also this weapon cannot mini-crit at all, so no crit-a-cola abuse

also it always crits on halfzatochi wielders