doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Help Identify Italian SxS Hammer Shotgun

left barrel is .040" a tight full choke
right barrel is .035" also a tigh full choke these guns were made for fibre wads so genenarlly shoot pretty tight with modern shells I have an Armi G Gamba that looks very much the same as your gun I opened the chokes up on it to .010" and .020" it is now much nicer to use
the 1.370 kg mark is the barrel weight a requirement at the time of proof if the barrels are wieghed and they are less than the stamped the gun is deemed out of proof (so adjusting chokes and forcing cones in Europe would render a gun out of proof)
18.3 is the barrel diameter the other number is the choke constriction 70 is the chamber lentgh not sure what the 20.3 is
check out your other post I posted some pictures of my Gambe for comparison

I don't think there's any hard and fast rule that adjusting chokes and forcing cones would render your gun out of proof. Certainly does not do so in England.

To the best of my knowledge, the Italian proof houses never required nor stamped the barrel with the weight. The only proof house that I know of that has done this is Liege.

Yes, your gun is safe to shoot with modern loads. It was proofed in 1958 so it is not that old compared to some here.

Pete

20.3 looks like chamber diameter in milimeters

I was of the understanding that the barrel weight was there as a reference from the time of proof and if the weight was different metal had bee removed and therefore the barrels were out of proof (I agree the choke shouldn't make any difference but forcing cone could as they are at the pointy end so to speak regarding pressure)
with regard to England I thought if you had the forcing cones done your barrels were reproofed? or maybe it is an urban legend? I had my barrels forcing cones a while back and remember seeinmg in the advert that the barrels were proofed after the work (which would have been hard when the barrels were all that was supplied no action went with them) this was from a "large" shotgunning gunsmithing franchise that has a shop in Australia (big enough hint without naming:))
intersting thread this I'm not trying to disagree with anyone just saying what my understanding was quite happy to be proven wrong

Hello Kid,

It is my understanding that the object of having the forcing cones done is precisely
to reduce somewhat the pointy end regarding pressure.

I don't know about reproofing but it shouldn't hurt.

JC

As I understand it, there are only two modifications to barrels that will automatically render a gun out of proof in England: lengthening chambers, and bore diameter no longer within specifications. Even wall thickness, just by itself, won't do it--although the British gun trade recommends a minimum. But there have been posts here previously by people who have had guns pass proof, or known of guns that did, with minimum barrel wall thickness below .020.