The problem with the gun is that it acts with the gem on it like it is not there, but after removing the gem, sound of the gun and the animations will get back how they are meant to be
There may have been problems with the sounds of the gun, since after around 2-3 games, the gun started to make noices of the normal sniper rifle again, but the new animations are working fine
I am not sure if the sounds may switch again for other people since I have done this only for myself yet