I just received my new to me Janssen Fils & C SxS. Well kinda received..for the 5th time this year my approval has been "Delayed". I know I need to get my CWP.

I have been trying to decipher the Proof Marks.
I figured out:
Black Powder proof.
Choke xx.x post used post 1924
S# 89736
Gauge & Length 20/70 post 1924

But nothing else, including the date and the smokeless proof

I was hoping to shoot it this weekend but now I have concerns as I am new to the Older guns

Thank you all so much

Jim

Odd that it has a 70mm chamber but not proofed for smokeless? Do you suppose the large number 2 means this was part of a set?

Well that is confusing.

As you observed, the 20-70 in the Omega is definitely post-1924.
There are not however lettre annales nor Smokeless Powder proof marks. Smokeless proof was obligatory post-1924.

Are the markings on the rib/barrels in English? It is not uncommon to see Belgian doubles intended for the U.S. market to not carry Smokeless Proof as there was an additional charge therefor.

'HS' or 'SH' could be the dealer? Spalding-Haywood Arms Co. was in Denver

The fluid steel barrels were by Laurent Lochet-Habran who supplied tubes to most of the U.S. double gun makers, including Hunter Arms, Baker and Ithaca.

If the wall thicknesses are OK, I would not be worried about the absence of Smokeless Proof. The rough forged tubes WERE proved before the joining and finishing.

I would think that the gun would be shown in the 1926 catalog
https://www.cornellpubs.com/old-guns/item_desc.php?item_id=3618

These pictures are all I have at the moment The ATF put me on hold until tuesday. But from what I remember the only writing was Dutch. I thought that it was "Janssen Son if made for the US market.

Is it Fils & Cie or Fils & Co?

It does look like Co, English my mistake.

Can the date of manufacture be discerned?

Are the inspectors' marks above the provisional BP proof marks star over L; If so should be Antoine Salmon 1937...1968.
Leon Chesnoy 1927...1955 & 1959...1968 for the star over Y on action flats.

According to "Gun Proof in Belgium" by Lee Kennett in the "1978 Gun Digest" under the system of 1924 the ordinary provisional proof for 20 gauge barrels complete save chambering at 11,700 psi was 11 grams of powder and 42 grams of shot and the definitive black powder proof at 9,100 psi for maximum chamber length of 2 3/4", 9 grams of powder and 33.3 grams of shot.

According to Kennett the two separate nitro proofs were "theoretically optional" under the 1924 rules of proof.

Markus

One last question; for now...

it says Choke 15.9 which translates to .626 I think...I was an English major...What does that translate as to today's choke nomenclature? IM?

The seller advertised them to be IC & IM .010 & .023. I'm confused...I will mic them when I get it home.

BTW: it is a pretty little gun, feels great in my hands, mounts perfectly with a 15" LOP, I am looking right down the rail. Next is to see if it shoots straight.

Thanks for your help in all this.

CHOKE means a muzzle constriction of > 2mm = about .008"

15.9 is the bore at .626" which is generous for 20g; standard is .615". You will need a bore gauge to accurately measure the chokes; not a simple rule gauge.

The 1924 rules mark does not give the diameter of the choked portion any more, just the unchoked bore size.

From littlegun.be:

JANSSEN Fils & Co (Banc d’épreuve de Liège 1895 – 1937) et sise rue Lambert Le bègue, 4 à LIEGE.

Etablissements JANSSEN Fils & Co S.A. (Banc d’épreuve de Liège 1937 – 1951 ) sise à LIEGE rue St Gilles,87.

Fabrique d’Armes JANSSEN Fils & Co S.A. (Banc d’épreuve de Liège de 1951 à 1954) rue St Gilles, 87 à LIEGE également.

Assuming the inspectors' marks add up manufactured 1937...1954 (probably little production during WWII).

Markus

I suspect it is pre-1937.

Quite possibly. Just saw a gun with a 1928 date code and the mark of an inspector who was not on the provisional list I was using from
http://www.shotguns.se/html/belgium.html

According to littlegun.be Laurent Lochet-Habran house established in 1860. Laurent LOCHET-HABRAN & G. frère et sœur operated under various names 1898...1951 and trade-marked LLH in 1904.

Markus