The first British HEAT weapon to be developed and issued was a rifle grenade using a cup launcher on the end of the rifle barrel; the Grenade, Rifle No. 68 /AT which was first issued to the British Armed Forces in the year 1940. This has some claim to have been the first HEAT warhead and launcher in use. The design of the warhead was simple and was capable of penetrating of armor. The fuze of the grenade was armed by removing a pin in the tail which prevented the firing pin from flying forward. Simple fins gave it stability in the air and, provided the grenade hit the target at the proper angle of 90 degrees, the charge would be effective. Detonation occurred on impact, when a striker in the tail of the grenade overcame the resistance of a creep spring and was thrown forward into a stab detonator.