When you experiment with every part the AR ever came with and make measurements.
An XM16E1 lower weighs 2.34 lb.
M16 (Late R604) and M16A1 lower is 2.27 lb.
Those have the rubber butt plate without storage compartment.
An M16A1 lower with the storage compartment is 2.56 lb.
The longer M16A2 lower is 2.43 lb.
An A2 lower with a Magpul MOE Rifle stock is 2.65 lb.
Just changing the buttstock can mean fairly large changes in weight.
An XM177E2 lower with the aluminum collapsible stock is 2.2 lb. Change that to the later fiberlite it drops to 1.87 lb.
The present M4 lower is 2.01 lb.
Going all modern and putting a Magpul MIAD pistol grip and a mil-spec CTR stock tares around 2.23 lb.
Magpul stuff just always seems heavier than USGI, doesn't it?
An XM16E1 lower weighs 2.34 lb.
M16 (Late R604) and M16A1 lower is 2.27 lb.
Those have the rubber butt plate without storage compartment.
An M16A1 lower with the storage compartment is 2.56 lb.
The longer M16A2 lower is 2.43 lb.
An A2 lower with a Magpul MOE Rifle stock is 2.65 lb.
Just changing the buttstock can mean fairly large changes in weight.
An XM177E2 lower with the aluminum collapsible stock is 2.2 lb. Change that to the later fiberlite it drops to 1.87 lb.
The present M4 lower is 2.01 lb.
Going all modern and putting a Magpul MIAD pistol grip and a mil-spec CTR stock tares around 2.23 lb.
Magpul stuff just always seems heavier than USGI, doesn't it?