diff --git a/Generators/ParticleGun/share/common/ParticleGun_EoverP_Config.py b/Generators/ParticleGun/share/common/ParticleGun_EoverP_Config.py
index 8b78a953f31c253a9ead42158bf4d8b0dab77ce0..aedf2d9f64e22aa04ef91e258864d97a1c48c491 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_EoverP_Config.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_EoverP_Config.py
@@ -13,8 +13,8 @@ class PEtaSampler(PG.MomSampler):
     def __init__(self, momentum, eta, pid=211, phi=[0, math.pi*2.]):
         self.momentum = momentum
         self.eta = eta
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        mass = pdg_table.GetParticle(pid).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        mass = pdg_table.GetParticle(pid).Mass()*1000.
         self.mass = mass
         self.phi = phi
 
diff --git a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_ChargeFlip_Config.py b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_ChargeFlip_Config.py
index a5399a64019b935aa729244f88c4b5c0ebe5b35f..ff578d3db5979cd4701f2411a1b92bcc7983341c 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_ChargeFlip_Config.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_ChargeFlip_Config.py
@@ -11,8 +11,8 @@ class MyParticleSampler(PG.ParticleSampler):
     def __init__(self,energy,eta,pid,shift_z=0):
         self.pid = pid
         self.shift_z = shift_z
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        mass = pdg_table.GetParticle(self.pid()).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        mass = pdg_table.GetParticle(self.pid()).Mass()*1000.
         self.mom1 = PG.EEtaMPhiSampler(energy=energy,eta=eta,mass=mass)
 
     def shoot(self):
diff --git a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config.py b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config.py
index 1b2e9a68bc5e1c1612bf2e294c58dcc472f700fb..c9551f643e3aff2a690e18a7177dd343b6e0caf4 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config.py
@@ -11,8 +11,8 @@ class MyParticleSampler(PG.ParticleSampler):
     def __init__(self,energy,eta,pid,shift_z=0):
         self.pid = pid
         self.shift_z = shift_z
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        mass = pdg_table.GetParticle(self.pid()).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        mass = pdg_table.GetParticle(self.pid()).Mass()*1000.
         self.mom1 = PG.EEtaMPhiSampler(energy=energy,eta=eta,mass=mass)
 
     def shoot(self):
diff --git a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config_Erange.py b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config_Erange.py
index 75ebc0621e7ba4e6803ae25c20a6d7438fc45466..92cfca9b96ce5f71fb9196e1d80d207964aa1004 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config_Erange.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_Config_Erange.py
@@ -11,8 +11,8 @@ class MyParticleSampler(PG.ParticleSampler):
     def __init__(self,energy,eta,pid,shift_z=0):
         self.pid = pid
         self.shift_z = shift_z
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        mass = pdg_table.GetParticle(self.pid()).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        mass = pdg_table.GetParticle(self.pid()).Mass()*1000.
         self.mom1 = PG.EEtaMPhiSampler(energy=energy,eta=eta,mass=mass)
 
     def shoot(self):
diff --git a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_NoChargeFlip_Config.py b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_NoChargeFlip_Config.py
index 7ba60ef2bc9d3a9195ada72e9a2232864f173567..cb6c9f8eb95ef30fdae7e1b71a55790cb68da85c 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_FastCalo_NoChargeFlip_Config.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_FastCalo_NoChargeFlip_Config.py
@@ -11,8 +11,8 @@ class MyParticleSampler(PG.ParticleSampler):
     def __init__(self,energy,eta,pid,shift_z=0):
         self.pid = pid
         self.shift_z = shift_z
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        mass = pdg_table.GetParticle(self.pid()).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        mass = pdg_table.GetParticle(self.pid()).Mass()*1000.
         self.mom1 = PG.EEtaMPhiSampler(energy=energy,eta=eta,mass=mass)
 
     def shoot(self):
diff --git a/Generators/ParticleGun/share/common/ParticleGun_SamplingFraction.py b/Generators/ParticleGun/share/common/ParticleGun_SamplingFraction.py
index 54557f0d5d2afacedb09999acac22e02ad8576ac..fa9a35d0df26246161f4a38150301d878b786e3a 100644
--- a/Generators/ParticleGun/share/common/ParticleGun_SamplingFraction.py
+++ b/Generators/ParticleGun/share/common/ParticleGun_SamplingFraction.py
@@ -17,8 +17,8 @@ class MyParticleSampler(PG.ParticleSampler):
         self.momentum = momentum
         self.eta1 = eta1
         self.eta2 = eta2
-        pdg_table = ROOT.TDatabasePDG.Instance()
-        self.mass = pdg_table.GetParticle(self.pid()).Mass()
+        pdg_table = ROOT.TDatabasePDG.Instance() #Gives values in GeV
+        self.mass = pdg_table.GetParticle(self.pid()).Mass()*1000.
         self.bec=bec
         self.radius=radius
         self.z=z