Straight from Remington
Choke constrictions are:
That is total so to get the actual restriction you need to subtract the choke diameter from the barrel diameter.
Typically it goes like this:
So based upon these numbers your barrel is around .727-.728
I didn't answer originally because I had never heard of a Singles choke.
I only watch brokeback mountain
Don't let your ears hear what your eyes didn't see, and don't let your mouth say what your heart doesn't feel