Your weapons squad still needs GPMGs because the best position to support and overwatch your maneuver element is rarely with the maneuver element, and if they are with the maneuver element they're slowing everyone down (a bit of a moot point in places like Afghanistan since everyone is loaded down like mules moving to contact with approach loads anyway, but that will get you killed against a competent enemy)

I think the GPMG will be supplanted by the LWMMG in the weapons platoon. And maybe a 51mm recoilless gun? 

Well, the US Marines are going to 84mm for every platoon..

Farmplinker said:

Well, the US Marines are going to 84mm for every squad.

FIFY.   ;^)   https://youtu.be/jfVxspzh0Pg?t=75

Thanks!

Is there an existing 51mm recoiless rifle?

Not that I am aware

In that case, how about 57mm?  Gun and ammo do exist.

The design and construction just need to be modernized.

https://www.youtube.com/watch?v=qsM8EtBZ-EQ

I have thought before a scaled down Carl Gustaf might be useful. 

Something like 66mm, akin to the LAW, but reloadable and more accurate. Similar to the relationship between the 84mm AT4 disposable and 84mm Carl.

66mm is .786 of 84mm, so just taking the M4 weights and multiplying by .786 as a guestimate: 

84mm

Carl Gustaf M4= 14.55lbs

Aimpoint FCS13RE = 3.53lbs

HE 441D Airburst = 6.83lbs

x3= 20.5lbs

= 38.53lbs

66mm

Carl Gustaf 'M66' =  11.44lbs

Aimpoint FCS13RE = 3.53lbs

66mm Airburst = 5.37lbs

x3 = 16.11lbs (x4 = 21.48lbs)

= 31.08lbs / x4 36.45lbs

gatnerd said:

I have thought before a scaled down Carl Gustaf might be useful. 

Nope it would be a dumb idea. 84 mm isn't very big and the weight is steadily coming down. A drop in calibre would give up all pretence of being anti armour. 

RPG 16 went the route of a higher velocity to increase range and accuracy

https://modernfirearms.net/en/grenade-launchers/russia-grenade-launchers/rpg-16-eng/

Airtronic went super lightweight materials. accuracy is poop but for launching guided projectiles it would be a starting point. 

https://modernfirearms.net/en/grenade-launchers/u-s-a-grenade-launchers/airtronic-rpg-7-eng/

Brute force and ignorance was the Breda folgore. This is a quite old system now and could be dramatically improved with lighter materials and more moder projectiles. 

https://en.wikipedia.org/wiki/Breda_Folgore#:~:text=The%20Folgore%20(Thunderbolt)%20is%20an,the%20Italian%20Army%20in%201986.

The endless search for super lightweight systems because troops are apparently too stupid to use a transport really needs to die.