doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Help identifying Spanish SXS

Good morning this is my first time posting on this platform but hoping to gain a little knowledge. I've got what I believe to be a late 20s to early 30's Eibar shotgun I'm looking to source a barrel for and I'm having trouble verifying the original gauge. 12 gauge is too big so I would assume it's either a .410 bore or maybe a 28 gauge? Hoping somebody on here is well versed in these old Spanish guns, I've attached pictures of the makers marks and some measurements.

Mr google says : The "JB" is the maker mark of 'Armas Bost', formerly under the name of 'Jose Bolumburu'.

There is a date code on the barrel flats and the bore in mm just forward of the flats; and possibly stars indicating the choke
.410 = 10.4 mm; 28 gauge = 13.84 mm

1965 catalog repro
https://cornellpubs.com/product/379...sTqM6UfPMSz39-LEtXUOqO6eDjYWKLPOtNbRcOJk

I would take it that the c.410.50 on the action flat indicates it was a .410ga chambered for 2 inch (50mm) shells.

Or an odd way of expressing the barrel weight at the time of proof
1.41050 Kg = 3.1096#

Having a hard time sourcing a .410 barrel with 2 inch chambers. Anyone know if a barrel assembly with 3” chambers would work? Also are all the Spanish guns under different importer names compatible? American arms, zabala,kessnar etc….

A good one-stop information post on the different shell lengths and the Babylonic name quandary (the same calibre going by .410, 36gauge, 12 millimetres, depending upon time and country) might be found here, too:
https://www.fourten.org.uk/36gauge.html

Carcano

Welcome to the Forum!

I can’t help but wonder if Senor Jose Bolumburu chase Bost as a trade-name, appart from its alliteration with “Best” , in the hope that the less discerning customer might confuse him with Thames Boss, purveyors of best guns only.

Nevertheless it is s neat little action, and I wish you well in your search for an orphaned pair of barrels to fit to it.

If you find a set (and fore-end?) be sure to buy a lottery ticket as your luck must be in that day!

I would tell you to start at Numrich Gun Parts, and when they tell you they don’t have barrels for it, sell whatever is left of the gun to them. At that point, take whatever they give you, and if the notion of a Spanish .410 intrigues you, begin the search for a functional gun.

You’ll have a couple bucks head start.

.410 double gun barrels would be difficult to source for that gun.

Best,
Ted

Entirely correct. Spanish artisanal shotguns are not composed of interchangeable parts.