Please d'nt be severe for my english which is very bad,i am french.I am an old gun user for uplland shooting when i was young,a shooter owning a Darne was very proud,as these guns were considered as very good ones.
Your Darne is stamped Type 10.It belongs to te R series (big key).
The R10 was the least expensive shotgun made by Darne,with case colored breech,few if any engravings .
A little more expensive was the R11 ,same gun except for the silver colored breech and light engraving.
These two types were the main selling of the Darne factory,each gunstore 40 years before ,in France ,had 2 or 3 of these guns for sale.
More expensive R13 and R15 types wore converging discs ,more fancy engravings ,generally they were obtained only to order.
The very best of the production were the V (little key) series with a different closing system,highly engraved.....and very expensive!!!So they are scarce ones.
The stamps on your gun mean:
65.....it is the length of the chamber (2 and a half inches)
three palms.TRIPLE EPREUVE...the barrels have been proof tested to 1300 bars (18500 pounds/square inch)The barrels only!!!!
PT with 1 crown.....the whole gun has been proof tested to 900 bars (12800 pounds/square inch)
18,2 .....it is the size of the bore in mm (0,7165 inch)
These Darne were very good guns for upland hunting: light weight and very good barrels ,very good patterns,able to shoot a lot of cartriges without any trouble ;and if wear appeared it was easy to correct this.
The only point of weakness is the screw fastening the stock to the reciever
ometimes it splits the stock just behind the reciever.It is a good idea to tighten this screw if any play appears.
You have a very good gun ,as long as you shoot ammunitions no more than 2 1/2 inches in length,it will last a lot of time.
I wish you a long use of your Darne.