Just after fixing one not serious bug, I now found 3 new ones in a row.
In all case, this happened when the player has 2 same pistols.
1) Buy another remington pistol, set weapon mode to akimbo, then prepare your weapon change menu as the following picture
Then drop the two pistols quickly.
You will notice that "Double pistols" will still be displayed as the following picture
Then press your fire button (mouse left button by default) and you will hear an infinite loop of weapon change sound
2) To find this one, you should try many times.
Set weapon mode to akimbo with same pistols too.
Drop the two pistols very very quickly.
Then pickup your dropped pistols, and you will hear an infinite loop of weapon change sound.
3) This one is probably annoying since it can be considered as cheat.
Set weapon to knife.
Then change to akimbo pistol and in the same time and very very quickly, drop the two pistols.
If you manage to success the trick, you will still have the two pistols in hand, but without ammo, and find two dropped pistols on the ground, with ammo filled.
In that situation, you cannot change weapon but what the hell, you have spawned two new pistols !
I just let you imagine a player doing this in Bank robbery with two Peacemaker