Hi Frank.
Rpr is the new ruger system right?
I have not seen anybody offering bolts and barrel extensions for the ruger. It will be tricky I think and I have been a bit disconnected from the sport and forums but check PTG and also with the ruger forum.
Sorry man, I cannot be more helpful.
I seen some aftermarket barrels for them in .308, 6mm Creed and 6.5 Creed, but didnt see anything that would use the .223 bolt. Doesnt the 6.8 spc use the .223 bolt?
Patriot valley arms does offer some replacement RPR barrels, but I don’t know if they offer 6.8. I ran across them as they offer a 6mm BR barrel for the ruger.