Shown below are two throwing dummies from Russia constructed to resemble a stickgrenade like the M1914serie.
It consists of a wooden handle with a heavy metal ring on top to copy the weight of a real grenade.
The ring was held to the body by one or two screws.

Photo on the right © Jhonni.

On the photo you see the "normal" type together with one fully made of aluminium.
The aluminium type was used in the 1970's and 1980's.

Photo © Cory.