3 grains of powder, we will use 115gr bullet = 129,800 grains.Illegal, but not unconstitutional. How heavy would an 1100 round magazine be on a glock? To shoot one handed, you’d have to in exceptional physical condition.
Per the internet, each casing weights 3.9 grams = 60.18 grains (we round to 60).
60*1100+129800 = 195,800 grains.
Weight if SPP = 3,520 grains + 195,800 = 199,320
199,320 grains = 28.47lbs. + 4 pounds for mag (guessing) = 32.47lbs
Since it is already illegal, might as well add a grip to the handgun, make it extra illegal to help support the weight.