I guess what stands out there is that it (7.62) is a heavy bugger.
The 7.62mm Main Battle rifles are heavier as a result of their cartridge and design purpose.
They all weigh the same.
G3:
10.81lbs loaded
FN-FAL:
9.25lbs empty
Loaded Magazine = 1 lbs 9.74oz
9.74 oz / 16 oz = .6lbs
Loaded Magazine = 1.6lbs
9.25lbs + 1.6lbs = 10.85lbs for the Loaded rifle
M14 rifle:
11lbs - .27 lbs for the sling = 10.73lbs
One could argue that the G3 has the heavier wood furniture and is lighter with the polymer, the FN-FAL would be lighter with polymer magazine or without carrying handle, the M14 could have been measured with the leather sling..etc...etc...etc
In the end the tiny fractions going back and forth does not change the fact that in any practical way, the rifles all weigh the same.
It is like the recoil impulse. The M14 and the G3 have the exact same recoil impulse as measured by the US Army. I am sure the FN-FAL is right there with them.
Why? Physics...same weight, same energy = same result. That is assuming properly set up and maintained rifle.
I like the G3 so much, I made my own out of a PTR 91 pistol.
Outside of the MP-5 which was the only real choice for so long if you wanted a modern sub gun...I was not a fan of the Roller Delay designs. For one thing, it lacked a bolt hold open function. I can remember as a private in 1/75th everybody just running down the AK47 and MP-5 for that reason. We had reload contest, etc....
It was only after seeing them in use on the battlefield, having to maintain the weapons as well as train soldiers using them, that I really came to respect the design. Familiarity did not breed contempt.