Some additional info:

The No.68 AT rifle grenade was, arguably, the first fielded HEAT projectile. It was first fielded as the Mark I in 1940 and was continually improved up to the Mark VI version when it was withdrawn from service in 1945. The average variant weighed 894 grams.

The HE cup was filled with lyddite, Pentolite or RDX/Beeswax depending upon version. The HE filling weighed 156 grams.