Laurona Eibar SxS Chamber and Choke Help

[Wanhope]

I recently picked up a Side by Side 12g Laurona Eibar shotgun at a gun show.

However I am unable to see what fixed chokes are in each barrel, the only markings relating to choke seem to be "Choke 17.5" and "Choke 18" on the left and right barrels respectively.

Secondly, there is no visible stamp for chamber length (there are lots of random numbers all over the underside of the barrel but nothing corresponding to the usual 2 3/4, 3, 3.5" markings.

There are also markings:
- a boxed [12-70] on each barrel
-Serial number on barrel and reciever
-shield and helmet marking
-cross rifles with a 2 overlayed
-barrel length (18.5)
-a shield with "BP" and an oval all within it.
-F.M. in an oval on one barrel.
- A handful of very sloppy part numbers and letters that seem to correspond to "1 5 U (or O, or 0) 0, G, a couple lower case blurred letters that might be MOS?
-the only marking on the receiver is the serial, and company.


I will put up pictures shortly as I realize my post is a cluster#&@$.

Any help is appreciated!

TL;DR: Need to know the chamber length, and fixed chokes on my SxS Laurona Eibar 18.5" 12g shotgun. Please help.

 

[Ahsan Ahmed]

The Laurona is equipped with 2 3/4in chambers (notice the "12-70" stamp on the flats i.e. 70mm being the chamber length)....fixed chokes on those older Basque guns usually left the maker's shop as F/M....hard to say what those would currently measure without placing a gauge in those particular barrels (may have been reamed since then).

You may decipher the various stamps via the following URL:

http://personales.jet.es/rafa/b_punzones.html

A bit confusing where you has stated "bbl length (18.5)" - likely indicates the CYL bore measure? Hard to say without looking at the bbl/action flats. I take it the bbls are still original i.e. 26 inches or over?

Prior to use, may be a good idea to have the firearm checked end-to-end by an experienced individual in order to validate overall sound health.

Recommend use light(er) shot shells - example: 1oz loads as that would subject the sxs (particularly the old stockhead) to lesser pounding.

 

[setter]

The 12/70 is 12guage 23/4 chambers or 70mm
18" barrels on a spanish gun I would guess no choke as likely the barrels were cut shorter.
Someone may know the rest of the proof marks.

 

[hunter5425]

I think the markings say your barrel diameter is 18.5 mm and the chokes go down to 17.5 and 18mm ( 1mm and .5mm constriction) making these modified and full chokes or there abouts.