Interesting site
 

http://proofhouse.com/index.htm

Have no idea how accurate this place is, but it appears to have a lot of good information.

Ed

That's one of my favorite sites for dating my Colt Police Positives. I've used it for about two years or so now and, so far, it has been accurate.

I've reccomended it to others and have never heard anyone complain about the info they got. I guess that's as close to an endorsement as I'm going to give...

There are deficiencies as to the Hi-Power dating.