Article 5 – 2011

Question: I have purchased a second hand trap gun which I am told is about 20 years old. Being reasonably new to the sport of clay target shooting I am a little confused about all the numbers and symbols on the barrel under the for end. Can you shed some light on this for me?

Eric Fontanna, Springvale VIC

Answer: Eric you haven’t told me what manufacturer your shotgun was made by, but I will give you some general details on what you will find under the for end on an Italian shotgun and most European brands.

You will see a number that reads “KG1.55” for example. This refers to the net barrel weight. For a typical trap barrel it can vary all the way from 1.45 kg up to 1.8kg depending on the length and rib configuration. Most 75 cm barrels with a standard height rib range from 1.5 kg to 1.6 kg.

There will be a figure with the numbers 18.4 for example. This refers to the barrel bore diameter. This can vary anywhere from 18.3mm up to 18.7mm on most Italian shotguns with 18.4 being the most popular over the past fifty years, but an American trend of having “over bored” barrel sizes showing some popularity in trap shooting.

You may see some small circles just in front of the ejectors on a twenty year old trap gun. On the top barrel a solitary circle will mean its is choked “full” and two circles on the bottom barrel will mean a three quarter choke or “improved modified” as it is commonly called. Some trap guns are made with a half choke or “modified” in the bottom barrel which is represented by 3 circles. Four circles is a quarter choke, but are never standard in any trap barrel. Later model barrels will simply print the letter “F” “IM” or “M” on the top barrel.

The only other important number on your barrel should be the stamp which signifies the length of the chamber. Most trap barrels will have “CAM 70” written on it which details the maximum length of the cartridge to be loaded in it, but there are quite a few which will read “CAM 76” which means it can take a 76mm or 3” magnum type shot shell. ALWAYS check this before you attempt to load a high performance hunting type 3” shot shell in any competition barrel. Competition shot shells are typically 70mm or 2 ¾”.

Under the bottom of the breach you may see certain symbols that relate purely to the proof testing of the gun at the time of manufacturing and on Beretta shotguns a couple of capital letters enclosed in a small square box which is a symbol which provides the code for the year of production. Above this row should be a 6 or 7 number which is the serial registration number of the shot gun itself. Check to see it matches the number under the top lever if it’s a Beretta to check it’s the same. Recently, with the help of the local police firearms officer, I strangely found one in my gun collection that was different.

I hope all this helps you out Eric. It is always useful to know.