so I would just buy the full size carbine, replace the barrel and shroud and it would be mass legal?It's kind of a wash. If you buy 16" MA compliant, you have a rifle stock already. You can then buy a $260 barrel/shroud kit and DIY the replacement (unlike an MP5, this can be done). You can then enjoy having both barrel lengths or sell the 16" one for like $75-100., thus being about the same as buying a pistol and later buying a stock. Plus, you don't have to convince someone in a free state to break down the pistol for you in two shipments instead of just selling the pistol to a free stater.