I would go with separate .223 and .308 cans. I want to get something for 7.62X39, just shopping right now, trying to pick a can. .223/556 is hard on a can. If you want to save money on suppressors get a .45 can to cover your pistol calibers.
why is .223 hard on a can? im no suppressor guru either as i only own a wopping 1 but have been considering my next one to be a 7.62 can to cover the rest of my calibers. ive not heard any negative to shooting a .223 through a 7.62 can before this.