Issue With New Guns

[SourLemon]

So, i've always had this issue with these guns, even on others servers that have had them. Randomly, the guns and my screen just shake violently and the only way to make it stop is to put the guns away, but it does it again when I take them back out, i'm not sure what causes this as sometimes I can go hours without it happening.
If anyone know how to stop this it'd be much appreciated.