There is just no comparison with regards to weight savings between the LSAT and the SiG.
CT ammo weighs roughly half of regular ammo and has smaller physical dimensions. Just changing the casing to polymer does not give you the same savings.
Polymer cased telescoped ammunition weight saving is 37% the same as conventional polymer cased. Sig’s ammo met the minimum reduction requirement of 20%. The “half” or rather 40% would have been caseless ammunition however that imposed the cost, reliability and complexity issues. Basically Caseless isn’t ready for prime time still. Maybe in the 2060s.
If the resulting weapon can really shoot 800m away then at least there is an excuse. Instead we get a 3-4 MOA gun that breaks its scope more often than not. Increasing precision probably has priority over trying to increase bullet size. The current M7, especially the shortened version, offer 0 benefits to range and penetration compared to a good old battle rifle.
This complaint is often repeated by people clearly never used an actual old battle rifle.
3-4 MOA is combat MOA. The M4A1 is rated to 3-4 MOA.
Sub MOA is a specialist weapon with special ammunition. A modified accuraized M4 will give you smaller groups so would a modified M14 will give you 1-2 MOA. Most combat ones 3-4MOA.
For combat purposes the M7 and M250 are firing high velocity high pressure penetration type ammunition. That’s not match grade. 3-4MOA is the accepted accuracy of a service rifle. With match grade reduced velocity reduced pressure more specialized tips you can get better dispersion.
The NGSW was driven by “Overmatch” the want of better range but especially better penetration performance with the proliferation of Level III equivalent armor. Intermittent caliber ammunition could penetrate such with AP ammunition but at significantly shorter ranges that the 300m most infantry combat is quoted at taking place.