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Norma Gun Works

Posted: Tue Jul 05, 2016 1:19 pm
by gunsforglory
Can anyone please educate me more about this gun. Like its engraving. Will post proof marks shortly.
Eagerly waiting for the experts opinion.

Re: Norma Gun Works

Posted: Tue Jul 05, 2016 1:33 pm
by mundaire
A Belgian made SxS hammered double, is all one can tell from the photos you have posted. The engraving is quite ordinary, does not seem to be anything special about it.

Re: Norma Gun Works

Posted: Thu Jul 07, 2016 6:17 pm
by gunsforglory
Sir, Thank you for your prompt reply. Being an amateur at it, I was excited about the engraving. Am attaching the proof marks. Regards to fellow IFGians.

Re: Norma Gun Works

Posted: Thu Jul 07, 2016 7:02 pm
by mundaire
The proof marks are Liege, Belgium proof marks. From a quick glance it seems to be a 12 bore, Nitro proofed, with a 75mm chamber length. I can make out 18.3 and Choke written on both barrels, but cant see the other number (should be in the form 18.x), which would give an idea of the kind of choke constriction. I'm guessing that the bore may be 18.4, in which case the choke would be a pretty open choke, just like skeet chokes. Probably meant for close range upland shooting.

Cheers!
Abhijeet

Re: Norma Gun Works

Posted: Thu Jul 07, 2016 7:50 pm
by Grumpy
Yes, Belgian. Engraving is crude but decorative. 12-Bore with 75mm ( 3" ) chambers. Definitive proof mark for Liege. Nitro powder proof mark. Inspectors mark. Chokes are both 18.3mm which is 0.720" .... Assuming the bore diameter is .729" that is .009" which is a light 1/4 choke - or just under what the American refer to as `Improved Cylinder`. Of course the barrels are odds on to have been lapped since the gun was built which would mean that the chokes are now tighter - if the lapping was done properly - or virtually non-existent if the chokes were lapped through. Marks are post 1924 and the gun itself COULD be 1924 or 1925 but I wouldn`t swear to it.
Need more photographs to show the rib and stock AND could do with knowing the barrel length. I can`t see the rib properly to check whether it is sunken or raised but 3" chambers would suggest a wildfowl gun or a live pigeon gun ....... but the light chokes argue against either usage.
Need the extra information to suggest a usage as I said.
What I am concerned about is the green crap that I can see along the under-rib, in the extractor channels and in the locking mechanism. I suspect that is either old acidic grease, a modern synthetic grease or copper grease. NONE of the three should be used on a gun in any circumstance. GET RID OF THE MUCK IMMEDIATELY before the gun is damaged !!!
J.

Re: Norma Gun Works

Posted: Fri Jul 08, 2016 11:04 am
by marksman
Please pardon me for deviating slightly but my 12 bore DBBL Hammerless Shotgun is described as having .005' constriction for right barrel and .012" for the left one. What do I make of it? Its a 2.5" chambered British game Gun. Does this make her Imp.Cylinder and Modified? Britishers never termed them the American way, at least those days.
Marksman

Re: Norma Gun Works

Posted: Fri Jul 08, 2016 11:42 am
by mundaire
@Marksman .005" would seem like Skeet and .012" would be something slightly tighter than Improved Cylinder. See http://www.choketube.com/customer-servi ... ormation-3

Cheers!
Abhijeet

Re: Norma Gun Works

Posted: Fri Jul 08, 2016 11:46 am
by Grumpy
British choke designations make more immediate sense than the `Americansher` but neither is superior to the other so I don`t really know why `Indianshers` should worry about it. As it happens, the terms are somewhat variable but as a guide .005" is Skeet ( sometimes known as `Skeet 1` ) and .012" is between Improved Cylinder ( .010" ) and Light Modified - sometimes known as `Skeet 2`( .015" ) Some authorities would describe .005" choke as `Improved Cylinder`. Does it help that you now know that your left barrel falls between two `Americansher` designations ? You already know exactly what your chokes are so how can an imprecise designation help ?
The British designation would be 1/8 choke in the right and 1/4 in the left by the way and are just as imprecise.

Re: Norma Gun Works

Posted: Fri Jul 08, 2016 11:51 am
by mundaire
@Grumpy - Are you sure about the 0.729" bore dia? I thought the old Belgian guns had much tighter bores, recall reading the figure of 0.725".

Re: Norma Gun Works

Posted: Fri Jul 08, 2016 12:47 pm
by Grumpy
.729" is notional 12-Bore which is 18.5166mm but some continental manufacturers adopted a 18.5mm ( .7283" ) standard and some Belgian gunmakers used a tighter bore in the region of .725" ( 18.415mm ) but probably intended to be 18.4mm (.7244" ) Why 18.4mm ? Who knows ? When all is said and done, bore diameters were devised by the British and those measurements make little sense in a metric system so there was some `rationalisation`. Until very recently, Beretta were `notorious` for their tight bores.
One cannot adopt a `probably .725" `standard for Belgian bore diameters because it was not a standard. Therefore one has to work on the basis of the accepted standard which is .729". You should, however, note that I said " `ASSUMING` the bore diameter is .729" " .......` I did not categorically state that the bore is .729" because one just cannot do so.

Re: Norma Gun Works

Posted: Sat Jul 09, 2016 3:10 pm
by gunsforglory
Thank you so much for the detailed info. Mind boggling knowledge IFGians.