[ChuckNorris]

What is the caliber on a 5.45X39?

 

[Bidah]

That is the caliber.

-Bidah

 

[deerhuntguy]

5.56 = .223, 7.62 = .308, so ... a 5.45 = about a .20?

 

[matt g]

5.45mm equals a little over .21".