Originally Posted By: Slowpokebill
...I hadn't noticed the powder type and max load were only used from 1897 to 1903. That gets me close enough. That is also confirmed here. http://damascus-barrels.com/Belgian_All_Proofmarks.html

I wonder what powder is ECM3 and what kind of pressure was achieved with a 33 grain max load.


You and thousands of others wondered the same thing. Some of those powders produced 6,000 psi while others produced 10,000 psi. The users of the day rarely had convenient access to the powder listed on the gun. As a result, a Royal Decree was issued in Belgium, 30 Oct 1897, that set the proof pressure at 8,800 psi.

Pete

http://www.damascus-barrels.com/Movie.html