Welkin, Alicia and Faldio make use of the M1911 as their primary sidearms and as such it can be assumed that this weapon is the standard issue handgun of the Gallian armed forces although it is not seen in any other hands but the protagonists.
Fictional Gewehr 41/43
The Gewehr 43 is the primary rifle of both Gallian Army and the Gallian Militia, these weapons are used by all military riflemen most notably Alicia, Welkin and Faldio.
Scoped
Scoped Gewehrs are used notebly by Faldio, Squad 7 members and some Imperial snipers
Fictional M1 Carbine
In distant shots of Imperial soldiers weapons that look like short black coated M1 Carbine are used.
Fictional MP40
A weapon that looks like an enlarged MP40 is used by Imperial army Shocktroopers
Fictional AKS-74U
Some weapon based on the AKS-74U appears as a standard arm of the Gallian military shocktroopers, notebly by Rosie
Model 24 Stielhandgranate
The Model 24 Stielhandgranate grenade used by the German army during the Second World war makes an appearance in Valkyria Chronicles as part of the large military memorabillia inside the Gunther house, the grenade is described to have been used in "The First war" by Isara, it is used by Alicia and is shown being thrown into a room during the second opening song.
RGD-5
The RGD-5 hand grenade is seen in the hands of a wounded Imperial army deserter, he uses this as a far greater persuasive tool to hold Welkin and Alicia hostage than a selfloading rifle, this handgrenade is standard issue to the Imperia Army.
Russian Nagant M1895
(Thank you to whoever provided the direction to establish this weapons identification)