This 223 barrel is great - SSK Firearms .223 Remington SSK-50/Contender Non-Threaded Rifle Barrel

I simply put it on my gen 1 contender frame, it fit nicely, mounted an old scope that would not adjust well,, and it shot groups that touch out of the box. I was using inexpensive 55 gr. FMJ’s. Interestingly, I forgot to take time to clean the factory oils out of it before firing. I’m a believer in SSK barrels.