BJW is currently the FBI code (used by states and localities as well) which refers to Blaser Jagdwaffen GmbH, Isny/Allgau, Germany. However, doubt BJW&Co. refers to Blaser.
https://www.michigan.gov/documents/msp/NCIC_Gun_codes_490348_7.pdfFollowing are a few references to BJW&Co found on the web..some of which may refer to your gun from posts several years ago. It looks like all of these guns on which this stamp occurs were in the 1860’s….some were English made with English proofs; they had various manufacturers names .. W. Richards, Powell, J.N. Scotts, Harris and Co, W. Moore. Wonder if BJW&Co might have been a barrel maker?
— B.J.W. & CO. - Marking found on an English made 10 gauge hammer double
http://www.cornellpubs.com/free-files/Shotgun%20Markings-Vorisek%20BW%20Portrait.pdf — 2009: I have a old double barrel shotgun that's stamped W. Richards. It also has a B.J.W&Co stamped under the barrel, with crossed swords and what looks like a crown stamped. Is this a Belgium or English gun? Anybody got a guess. I'm not having any luck online. Seems to be Belgium..but I can't find anything about the B.J.W & Co. stamp.. It's been in the family for ever
http://www.gunvaluesboard.com/i-have-a-o....-17471218.html— 2011: I am trying to find out some information on a sxs shotgun . On the side plates engraving (bird dog and pheasants) with the word POWELL there as well. Under the breech area ther is the words B.J.W. & Co., along with a possible serial number. Two sets of makers marks. This gun has double triggers and s-type hammers. Firing pins appear to be of a pin (nail) type. The gun was purchased between 1860 and 1865 new.
http://www.gundirectory.com/forum/viewtopic.php?f=9&t=4603— 2010: I have an old shotgun that I can't seem to ID. The markings are B.J.W & Co. It is a break action with two triggers. I believe it is a 12ga but there are no markings about the gauge. If you know anything about this gun I would appreciate any input. Thanks.
https://www.shootersforum.com/shotguns-shotgunning-shotshell-reloading/64199-help-id-my-old-gun.html— J. N. Scotts Percussion Shotgun Manufactured circa 1860-1880. "B. J. W. & Co" along with some Birmingham proofs on the bottom of the barrels. Manufacturer: English Model: Side By Side BBL: 36 inch solid rib Stock: walnut Gauge: 12 Finish: brown/casehardened Grips: Serial Number: NSN Class: Antique Condition: OF - FAIR: some major parts replaced; minor replacement parts may be required; metal rusted, may be lightly pitted all over, vigorously cleaned; rounded edges of metal and wood; principal lettering, numerals and design on metal partly obliterated; wood scratched, bruised, cracked or repaired where broken.
http://www.invaluable.com/auction-lot/fo...90-c-672487ab85— Cowan’s Auctions; Double Barrel Shotgun by Harris and Co.; Lot #: 537;
12 gauge, 28.375" laminated steel barrels, English proofs, B.J.&W. Co. markings inside.
http://www.bidsquare.com/l/537/double-barrel-shotgun-harris-and-co— I have recently come across W, Moore shot gun. After reading some of the old blogs it seems that it could be a nock off so I'm wondering if any one can tell me if it is the real deal and a little more info about it. Thanks so much. here are some pics of the gun.
http://photobucket.com/Bullrun78 http://forum.mlagb.com/YaBB.pl?num=1250607869