>>536849116
>what makes bullpups ergonomic
They're not. For the most part they're unergonomic.

Rifles with longer barrels generally benefit from things like higher muzzle velocity and greater precision than similar rifles with shorter barrels. A standard rifle with a long barrel can be unwieldy in close quarters combat, or can be awkward for infantry that are disembarking from a cramped fighting vehicle. Shorter barrel weapons like submachineguns solve the size problem but suffer from the precision/muzzle velocity problems inherent to having a shorter barrel.

A bullpup attempts to achieve the best of both worlds by allowing the weapon to have a longer barrel length without increasing the overall length of the weapon. However now the downsides relate to the ergonomics of the weapon. The trigger assemblies tend to feel looser than those of a standard rifle since they need to make use of a linkage between the trigger and action. The center of mass feels awkward for soldiers trained with conventional weapons. Bullpups can be uncomfortable to reload, especially from prone positions. Bullpups can be more complex to maintain and repair than standard rifles. Many, but not all, bullpup designs can not be properly shot from all positions by ambidextrous shooters that want to fire from alternate shoulders.