I bought an Encore rifle last Sunday. The buttpad has it quite legibly molded into it that federal law requires a barrel of 16" or more to be used with a full-length buttstock. The Contender/Encore system is designed to have barrels and buttstocks interchanged. It is up to the user to recognize that pistol barrels of less than 16" cannot be used with a buttstock. Just be aware of that and adhere to the law-- you'll have no problems.