The holster that you have pictured there is the Bianchi Model 27. It was revolutionary in its day and was, I believe, patterned after the old Berns-Martin speed holster. It is a thumb-break holster. The snap showing on the side of the holster is "false" and it was believed that should someone try to take your weapon they would grab for the false snap thus giving the officer time to react and defeat the attempt. In order to draw you broke the thumb-snap and then pivoted the gun forward on its muzzle. As the frame cleared the holster you snapped the muzzle free and then up and forward to the target.

I still have mine for my 4" Colt Python. In the brochure that came with the holster it is simply referred to as the "Bianchi Break Front Holster". The bottom of the holster enclosed the muzzle of the revolver. At one time it was standard issue for the LAPD & California Highway Patrol. With practice you can be very fast. Like all holsters, including those in use today, it was not "snatch-proof".

The holster that followed this was the Bianchi Model 2800 holster. It had an open muzzle at the bottom of the holster and was known as "The Judge". I had one of those for a S & W Model 66 revolver and wish I would have kept it also.

I found neither of them heavy and both were very well engineered and manufactured.

Joe