I have a custom barrel chambered for 5.45x39mm and was thinking to use this barrel for shooting milsurplus ammo. I have Stevens 200 action that came form .223 rifle. I know that 5.45x39mm and based on this cartridge 220 Russian and 6mm PPC rounds are too big for 223 bolt face, but looks they are also too small for 308 face. Would it be feasible to open up 223 face, or is there a dedicated bolt head I could swap? Will 223 extractor work with 5.45x39 cartridge? I was also wondering if 5.45x39 would fit into .223 magazine. Thank you!