Oh dear. I really hadn't wanted to get into too much debate about Captain Newton and his eponymous grenades.
Lander deals with the background etc, probably much assisted by Norman Bonney of course.
And mon ami Doctor is quite right in that the original grenade was for rifle use, and called the Pipppin Rifle Grenade, the rod being secured to the base, or larger part of the body of the grenade itself. That finally was sealed as Grenade No 22, wch is why I was so careful in my wording, with the body being reversed, as it were, on the rod.
The indefatigable Newton then adapted the body of his rifle grenade, NB NOT the No 22, less rod, for hand use, wch is the version I illustrate.
The first Mark of the No 22 suffered from prematures, the bane of rifle grenades, of course, resulting in the Mark 11 wch had some relatively minor modifications to the body and a cap made of heavier gauge steel, thus dispensing with the need for a safety pin.
I think that covers it, as briefly as I can.
Alan1.