GOSAFE Act

Gas-Operated Semi-Automatic Firearms Exclusion Act or the GOSAFE Act
This bill establishes a framework to regulate gas-operated semiautomatic firearms and large capacity ammunition feeding devices under federal firearms laws.
First, the bill generally prohibits the import, sale, manufacture, transfer, receipt, or possession of
- a firearm that is or is modified to operate as a prohibited gas-operated semiautomatic firearm;
- a combination of parts that modify or can be assembled into a prohibited gas-operated semiautomatic firearm, or that produce an unlawful gas-operated semiautomatic cycling action;
- a device or combination of parts designed to materially increase the rate of fire of a semiautomatic firearm; or
- a firearm that is modified to materially increase the rate of fire.
Second, the bill generally prohibits (1) the import, sale, manufacture, transfer, or receipt of a large capacity ammunition feeding device; or (2) the possession of a large capacity ammunition feeding device manufactured after the date of enactment. 
A violation is subject to criminal penalties—a fine, a prison term of up to 12 months, or both, for each violation. 
In addition, an individual who possesses a prohibited gas-operated semiautomatic firearm during a federal felony offense is subject to additional penalties—a fine, a mandatory minimum prison term of two years, or both.
Finally, the bill allows a state or local government to use Edward Byrne Memorial Justice Assistance Grant Program funds to compensate individuals who surrender gas-operated semiautomatic firearms and large capacity ammunition feeding devices under a buy-back program.