Im wondering if the RG 316 coax could work for use with a CB or does it need a larger size coax?
Thanks,

 

What he said. As long as it's 50 Ohm and you can find connectors to build it yourself or find it with the correct connectors in a usable length.

 

I've never seen anyone use something that small for an antenna install. That looks like the kind of coax that's used between modules in the military radios I used to work on. It's only about 1/10" in diameter. There are connectors for it, but they are usually miniature. I do recall a BNC connector that had an adapter for the 1/10" diameter coaxes. Then you may be able to come up with a BNC-to-PL-259 adapter. Personally, I'd recommend sticking with something like RG-58.