New British Military rifle?
A lot of thought needs to be given ti this and exactly what is its role going to be for. Rather it being the perfect rifle for say the Rangers, Pathfinders, Paras or Marines it is probably better to consider it for vast bulk of the military who specialist infantry, but rather general everyday soldiers, sailors or airmen where the main weaponry will be much larger machinery. The need fir a rifle is then for defence / close quarters.
Lightweight, easy to shoot and maintain, lightweight ammo and cost point is probably far more important.
We do need to reestablish our industrial base. Indeed we have plenty of skills in precision machinery. No reason why the new should not be built in the UK and become basis for a good export product. By all means take inspiration from elsewhere but if we are serious about UK military independence and strength we need our own capability to manufacture on this little island. If we can produce jet engines, then we can produce rifles.
I would also look at a design where by a non auto / non self loading civilian version could easily be built and for this to be the basis of cadet and civilian target shooting under the NRA, with a view to pushing target shooting again so that wider marksmanship skills available if / when they are needed.
Cartridge needs to be easy to shoot, effective out to medium range and cheap. 5.56 in its current format probably meets this requirement for vast majority of rifle use.
Going back to specialist infantry units where they are fighting on foot and rifle is the principle weapon, those units with a range of weapons and cartridges so they have to hand the best tools for the job in hand. It’s probably a mix of weapons in any particular unit with individual soldiers and squads having specialist as well as generalist skills and weapons. This is where the more powerful 6.5, 277, 308 and longer range 338s etc all have their place alongside a basic 5.56.