sentences:  For rifles fitted with folding or telescoping stocks (such as U.S. Carbine M1A1), US Federal guidelines state that measurement is performed with the stock unfolded as intended for use as a rifle.Some states — such as California and Michigan — measure overall length with the stock folded.Barrel length is measured from the end of the muzzle to the front of the breechface, typically by inserting a measuring rod into the barrel.