Because it is...;)
How much does it weigh
4.5 pounds. Note that is with two empty 10 round magazines in the stock as well.
how much does a typical AR-15 weigh?
The 16" barreled, 5.56mm DPMS is about 8 pounds, and the 16" Rock River Arms is about 7.5 pounds. The Ruger SR556 is 8 pounds. Most AR-15 builds are in the 7.5 to 9 pound range.
The little KT is really a VERY light rifle! Lighter than most 22LR semi-auto rifles.
That isn’t the model that you own though, you were pushing the SU-16.
You own the SU-16 which weighs 5.01 pounds,
my Bushmaster weighs about 7.2 pounds.
If the Kel-tec weighs from 4.5 to 5 pounds and the AR-15 weighs from 5.5 to less than 8.0 pounds why do you keep saying that it weighs twice as much.
It sounds to me as though it would be as little as a few ounces to about a three pound difference.
FWIW - I once owned a .357 mag PISTOL that weighed 4 lbs! It was like shooting a 22...