You don't have to create a skeleton, it's always the usslodier.ske that's used
and most of weapon's animations are tweaked from the first weapon dice devs made (might be m1 garand)
It's about importing .baf, mod and export them.
When you import a .baf, you can move the bones and save their positions using the "set key" in max then overwrite the .baf
The trickiest is the 1pReload with sometimes more than 100 frames...but once it's done you can copy it and use it for
1pLieReload...
When you tweak an existing baf you also can delete keys you don't need and then adjust the set1pAnimationSpeed and set3pAnimationSpeed in the tweaks con files, but then the soundscripts might not be synchro
Anyways lots of files in animations folder are copies