How can I bind a specific key to a specific weapon?

Firstly thank you for sharing this amazing game with us!!!
I absolutely love it.
Lets say I pickup a mine, and then a grenade.
Then I bind mines to X and grenades to C.
If I run out of mines and grenades, or I die and respawn.
Then I pickup a grenade, then a mine. Now X will be bound to grenades and C will be bound to mines.
I find it impossible to play like this, so I end up not picking up grenades because it's too confusing when my key bindings swap around all the time.
Is there a way I can bind a specific weapon to a specific key regardless of what order I pick them up in or what weapons I'm holding?
I absolutely love it.
Lets say I pickup a mine, and then a grenade.
Then I bind mines to X and grenades to C.
If I run out of mines and grenades, or I die and respawn.
Then I pickup a grenade, then a mine. Now X will be bound to grenades and C will be bound to mines.
I find it impossible to play like this, so I end up not picking up grenades because it's too confusing when my key bindings swap around all the time.
Is there a way I can bind a specific weapon to a specific key regardless of what order I pick them up in or what weapons I'm holding?