Can someone measure the barrel diameter where the FSB mounts on thier PSA Dissipator with the FN barrel?

I have purchased a PSA Dissy upper without the FN barrel and the barrel measures .735". The problem is that the FSB inside diameter is .750". I am wondering if the FN barrel is a true .750" in which case I will return this upper and exchange for the Dissy with the FN barrel.

FWIW, my RRA measures .740", so I am not at all saying that PSA isn't good stuff. I am actually VERY impressed with everything else about the PSA upper.

Thanks