You might want to take a look at the .327 Federal though. Looking at the numbers on it, it would appear that it has the same potential that you are looking for or better and one those is on my prioity list.
Ever seen a FMJ .327 round? Hell, have you ever seen ANY revolver caliber with FMJ bullets?
You are right that the .327 is very similar to the 7.62X25 in terms of bullet diameter and velocity, but if you have to use semi-wadcutters in your .327 you aren't going to penetrate the vest.