The issue frequently arises as to whether a Federal Firearms Licensee (FFL) in Pennsylvania must complete a PA Application/Record of Sale (Form SP 4-113) for the sale of a receiver.
To the surprise of most FFLs, the Pennsylvania State Police (PSP), as of 6/2/2011, has stated that no PA Application/Record of Sale should be completed for a receiver, even if that receiver is a receiver that can only currently be used as a pistol (AKA a Colt 1911 receiver), unless, the customer specifically requests that the receiver be transferred as a handgun.
So, why would a customer want a receiver to be transferred as a handgun? Take the situation where the customer owns a transferable Heckler and Koch sear trigger pack and desires to be able to use that sear on a new MP5 clone that he/she is going to build on a virgin receiver. If customer has the virgin receiver transferred as a pistol, so long as that individual does not place a stock onto the receiver, he/she could save the $200 tax of having to register the pistol as a Short-Barreled Rifle (SBR). When the customer places the trigger pack onto the clone MP5, he/she would be lawfully allowed to place a stock on the firearm, as the machinegun designation trumps all otherNFA classifications. Of course, the individual would have to remove that stock from the firearm before removing the trigger pack and could never place the stock on the rifle absent the trigger pack being installed.