Start editor
create default rifleman
preview
drop your rifle
point at it until you see hand
execute
player action ["TakeWeapon", cursorTarget, "srifle_GM6_F"];
You now have sniper rifle on your back which was not in the weaponholder. Do it again and again and many sniper rifles appear in the weaponholder.
This is because takeWeapon puts sniper rifle first in the holder before taking it out. If you have rifle already it doesnt take it so only puts.