I show two 1" Nordenfelt projectiles which look like Mk1V projectiles.
Some vandal has stripped the brass jacket off and I show a steel core.
It has the 6 groove cuts to stop the jacket from spinning around the core (I guess).
You seldom see this core as a separate item.
It weighs 6.2 oz. 178 grams . 2747 grains.
Complete projectile weighs 7.1 oz. 203 grams. 3133 grains.
Books say 3170 grains so a bit lighter than standard weight.