Combat and Survival has an article on the prototype rifle British forces are testing on. This is supposedly a part of SA80A2 Mid Life Improvement project to lengthen the service life of the gun beyond its 2025 dead line.
http://www.combatandsurvival.com/uk-news/7908-new-sa80a3-assault-rifle-revealed-dvd16
Some improvements are,
Full Picatinny rail on top
KeyMod
Freefloating barrel
From: Combat and Survival
