how to block stack duping with this mod?

I'm having the same issue with my server. Spawn 2 exact guns, seperate them, unload one set of ammo, then drag the empty gun to the full gun, then seperate them back and they both have full ammo. Players can FULLY dup Ammo.

I just tried it with M249's all three empty, loaded one with 100 rounds then restacked them, split them and one had 100 rounds the other two had stock 15 rounds each, still a problem but not that great, if you are worried about it stop them stacking rifles and auto weapons,

What @pookins said. Disable weapon stacking, problem solved :)

and how do you stop weapon stacking

Set all weapons to 1 in the config. 

thanks!

Just make sure you go through the Datafile and check that all the weapons you dont want stacked are also set to 1 there as well,

Stacking guns and duping ammo is a known issue, I'm currently in the (very delayed) process of trying to work around it. Setting the stack size of all guns to 1 will prevent this issue, as other users have said here.