They will "fit" but they will not fire correctly, and will break when the bolt tries to push two of them at once.
No. You can not shoot 40 cal out of .68 or 50 caliber markers.
Not recommended
maybe 80 feet at 45 degrees
Any round pipe can shoot darts that fit inside it. I would not use it as a dart gun however.
No, never attempt to fire ammunition in a weapon it was not designed for!.
No
No. Only shoot the caliber printed on the barrel.
you get what you pay for.
Maximum range of a .40 cal pistol is about 960 meters. ACCURATE range is about 50 meters.
Yes and no. The. 40 S&W is not interchangeable with the .357 Magnum, if that's what you had in mind. Most .357 Sig pistols can, however, but a .40 barrel will have to be dropped in in place of the .357 Sig barrel.
Depends on who made it.
No
40-150