TerraN_EmpirE
Tyrant King
When we look at most So called modular weapon systems, they are constructed around a "Universal Receiver" that serves as the core of the weapon.
That is both the Strength of the System and the Failure. the Strength of the system as if you look at weapons like the AR15 series or AK series the different main versions make alterations to the Receiver sets depending on versions. The M4 for example differs from the M16A4 for example by the addition of feed ramps from the barrel extension into the upper. In the AK Series the AKs74U, AK74/AKs74 and RPK 74 all have different receiver sets. by having a common receiver you you can in theory same money and simplify construction. The problem is this limits you to a specific operation type that is Closed bolt magazine feed.
If you look at dedicated Saws like the Ultramax it's a open bolt. This vents excess heat and allows safer operation of extended bursts by preventing cook offs.
now a weapon like a XM8 could be configured to that but it would require a modification to the operation of the weapon necessitating an alternative Receiver.
furthermore Although the Ultimax is magazine fed most purpose built LMG's are Belt fed, this allows larger belts of ammo to be assembled and loaded though the weapons with the Links not just ensuring feeding but also aiding in heat dispersal. And finally Dedicated LMG's have quick changes barrels. These are all features that are far more specialized and cannot be integrated into most universal receivers although there have been two that have found a way to do it.
The Stoner 63
Carbine, Rifle, Magazine feed LSW, Belt fed LMG, Belt fed GPMG, Coaxial MG. How? the upper and lower receiver module could be Flipped over and reconfigured into a Belt feed LMG or Closed bolt magazine fed rifle. This was a True modular weapons system. sadly it never caught on.
This is another to The AR15,
over the years a number of times makers have used the AR15 lower receiver as the basis of a Belt fed LMG. the Colt Machine Gun-1 or the Modern Fetherlight MCR
It's basically a SAW but on an AR lower. All the advantages of the SAW in an AR platform.
