[LW McVay]

The rare Bureau Models have serial numbers that begin the FBI as the prefix. The slide is also marked Bureau Model.

The Pro Model is the same as the Bureau Model with the exception that the serial numbers begin with a CRG prefix (rather than FBI) and the slide is marked Professional Model (rather than Bureau).

Same exact gun otherwise.

As Dave said, only 268 Bureau Models were made. Of them, I have no idea how many made it into "civilian" hands...the rest of course went to FBI Agents. The serial numbers and the slide markings changed but the gun (the Pro Model) continues to be an issued weapon.

If you have a Bureau Model, count yourself lucky.

 

[LW McVay]

No they are the ONE AND THE SAME.

Bureau Model = Professional Model.

The difference between the two is what I've already stated. Springfield was asked/told, whatever, to change the name and serial number of the guns if they were going to offer them to the public. The Bureau is very protective of its name and three letter identifier. Plus it is probably against some federal law or something...Ergo, SA stopped marking them Bureau after the number 268....