Frank ,I tryed a piston kit on my Bushy ,It was a waist of money. So i bought the XCR ,after the break in period it works great ,and the entire rifle cost as much as some company's uppers.At first i had my doubts ,but now the XCR works as good as anything i have ever had. The Bushy has the CQT sight ,even a woman who never fired a rifle can pick this up and hit cans at 150yds. OH the chicks think they bad ,i tell them the gun is a better shot than they are ,your just holding it. The XCR has the EOtec 552 , the CQT is a better daytime sight ,the 552 is better at night because of the large window.In daylight though i like to get away from the 552 and go iron,and you don't need to remove the 552 to use iron. But back to your question,save up,get an upper, and stay away from after market gadgets.