Janssen & Sons shotgun

[Bob]

Does anyone know if they can handle regular 12 gauge shells. Its called THE INTERCHANGEABLE with marks like 18.0 over 18.0 and AC over CI in a circle, 12 over c in a diamond on the underside of the barrel. We finally have some grouse running around and would like to take the hammered gun out.The reason I ask is the barrel has a damascus finish but its worn off near the action....Bob

 

[BEARMAN]

It probably is chambered for 2 1/2 in shells , 2 3/4 in shells will fit into the chamber but there is nowhere for the crimp to expand to, so you get very high pressures. I believe that most Damascus barrel failures were from 2 3/4 in shells being fired in 2 1/2 in chambers that from plain weak barrel failures, but that is just my opinion. Only a gunsmith with the proper gauges can tell if the gun is okay, if it is the chambers can be reamed for 2 3/4 in . But it is still a 100 year old gun, keep the pressures low. There are some low pressure loads using Federal paper cases, FED 209 primers, 7/8 oz. of shot and FED 12SO wads and small charges of BULLSEYE powder that have an approximate pressure of 4,500 psi. There are also some low pressure loads using the same components and low charges of RED DOT powder( these loads are under TARGET LOADS in the RELOADERS GUIDES distributed by Hercules or Alliant or whatever the company that owns them now is called).Regular 12 gauge shells are usually over twice that pressure. You could also check the proof marks on the barrel to see if it has been proofed for smokeless powder Do a search of "Belgian proof marks" or " Proof Marks" also goto www.republicmetallic.com/page12.html ALSO http ://www.bluebookinc.com/Info/PDF/Firearm/Proofmarks.pdf If you type in this last URL and add a "s" after the http it will take you to a wonderful site of PROOFMARKS.