Particle Accelerator is the only gun that can do one shot one kill on 300+ hp character in the right circumstance. (target gets knockbacked into a wall)
In my opinion, such gun shouldn't exist because it doesn't promote teamplay.
As a user, you are rewarded with a kill but you didn't need the help of your team at all, no target focus, no target calling, just one shot one kill.
As a target, you get killed but there is no team counterplay around it, teammates couldn't heal you, couldn't smoke you, just one shot one kill.
Extremely selfish gameplay.
Don't get me wrong without the one shot one kill mechanic, I still think Particle Accelerator is a worse version of DSR and AS50 because long charge time, long reload, slow easy-to-dodge bullet, knockback giving out shooter position, very specific gun sound.
Usually, I don't like to propose changes before hearing other opinions but this one is easy so here we go :
Reduce overall damage
or
Add a fail-safe mechanic to prevent one shot one kill
or
Rework it completely
or
The user also get killed (pls no)
TLDR: