The crits from behind only goes for melee(Or the Mouse 2 attack, M2 means Mouse 2.)by the way. Clip size increase makes it feel like a pistol, with 12 shots.

Only a 10% dmg bonus, because this could be really OP, M2 knife attack, short range, Mini-Crits from behind for M2, -5% damage bonus with knife. -5% slower swing speed/shoot speed

The only problem I have with it is the 20% dmg penalty. Being marked for death is already bad enough. For the rest really cool idea.

Why not make it a melee and have the soldier hold it wrong?
+25% damage bonus
-15% range
Crits cause bleed for 15 seconds but do mini-crit damage

Other idea:

Pros:
Same damage as revolver
First bullet in clip is always 100% accurate
Has 8 shots
Alt-fire: Melee attack with +25% faster firing speed but -34% range

Cons:
No melee weapon
No random crits on alt-fire

Weapon is a Pistol instead of a shotgun.

+25% Damage bonus
-33% clip size (8 shots)
same reserve ammo as scout default pistol
+30% tighter spread (more accurate)
-20% slower firing speed
disables access to melee weapon.

Alt fire is a melee swing, does stock melee damage with a 10% damage penalty, random crits enabled and at same % of normal random crit melee weapons, alt fire can be used with no ammo.

and for ♥♥♥♥♥ and giggles - Decapatates on crit alt fire kill
Can be used in Midevil mode, but no ammo is given, in this mode it applies bleed on hit for 4 seconds.

Acts as a Scout/Engi's pistol
-35% slower firing speed
+50% larger clip size
+15% more accurate

+20% more accurate
+10% more damage
+On Press M2: Slash with knife for a melee attack, minicrits from behind
-No melee weapon
-10% clip size
-15% firing speed

!Works like a Scout's pistol!
+alt-fire: Use the Knife for mele Fight

Knife does the same Damage as normal Shovel

Advantages:
10% Firing Speed
15% Secondary Ammo
M2 Deplot Knife

Disadvantages
-10% Reload Speed
Replaces Melee Weapon

This isn't a shotgun, it's a pistol.

The General Issue :

+ 15% More damage
+ Enemies bleed for 6 seconds on hit

- 25% Slower draw time
- 25% Slower reload

Crafting recipe : Pretty Boy's Pocket Pistol + Big Earner + Scrap = The General Issue

Right click to melee, and knocks you back when shot

7 Round Mag, +20 Damage Bonus, Equips/Holdsters 15% Faster, 75% Less Bullet Spread, +10% Firing Speed, Right-Click to stab, Mini-Crits on backstab, Replaces Secondary & Melee.

How bout this? If hit from behind its a backstab?