I own a NEF single shot, and have 5 different barrels for it. They are easy to change, but the factory says that each barrel, must be fitted to each receiver. Their claim that barrels from rifle to rifle are not interchangeable. I hade to send my receiver to the factory, and they made the barrels I ordered to fit it. I am not impressed with mine, fired brass sticks in the chambers, and accuracy is nothing to write home about. Just my 2 cents.