You mean actually chamber it themselves, cut the threads, bed, the whole bit? I have had a few built. Kinda came to the conclution, that its not worth it, and doesn't guarantee you a sub.5MOA gun. There are so many quality factory guns under 1200 dollars out there, that holds resale, that its not worth it for me to do it any longer. I mean its nice picking out your own conponents. But rather pricey.