Perhaps the pistol doesn't need a special feature.  I read that the ROF you show on the image gallery are based on rounds-per-minute.  In that case, if the Doom Pistol is 150 RPM, then the Earth pistol (if we wanted the exact speed of the WOLF3D variation) would be somewhere around 160-162.
So if we were to compare:
Doom Pistol:
Damage = 12
ROF = 150
Earth Pistol:
Damage = 10
ROF = 162
Doom's spread is a little looser, but it has first shot accuracy and does more damage, although at a slower rate.
Earth's spread is pretty tight, making most shots fired hit the mark (and fire at a faster rate).  However, it does less damage.
This sounds like its pretty balanced, but I could be wrong.
And don't worry.  I'm not taking this completely seriously (despite that I'm putting a lot of thought into it  

).  I don't expect anything to be implemented, unless everyone on the team agrees.  You guys have the final say on everything.  I'm just tossing around ideas.