Article 4 – 2013
Question: I am uncertain what height stock I need to buy for my new shotgun. I mainly shoot clays and plan on shooting trap and sporting clays. I was told I need the stock to measure 35mm if I am going to be able to shoot trap. I have no idea what that means. Is this a standard measurement and is it written somewhere on the stock of the shotgun?
Ian Clayton, Brunswick VIC
Answer: Ian the height of your shotgun stock is similar to your shoe size. Everyone has something a little different. On some brands of stocks the measurement can be color coded on the inside of the neck of the stock where it joins the action, but this is not typical of most manufacturers.
The measurement you were quoted for your trap stock of 35mm is probably the height of the comb at its front edge (the point closest to the barrel). I will quickly explain how this is measured. If you run a straight edge along the top of your barrels rib, a one metre metal ruler is perfect, and let the last 50 centimetres of the ruler overhang the barrels over the top of the comb. From this point get another smaller ruler and measure the distance at ninety degrees from the very top point of the comb to the bottom edge of the ruler. This measurement could typically be anywhere from 30mm to as much as 40mm on any stock. 35mm is probably a good average height at the front of the comb, but it is no means perfect for everybody.
Once you have the measurement at the front of the comb go to the very back of the comb where the recoil pad joins the wood and take another measurement. From this second measurement you can now calculate what is called the “drop” of the comb. On a typical trap stock that we often see imported into Australia on flat rib shotguns the drop measurement will be 10 millimetres. Using our average height of 35 mm at the front of the comb this would mean the height at the back of the comb is 45 mm, thus a difference of 10mm. On Sporting shotguns the height at the front of the comb may be 38mm with a rear measurement of 58mm. The extra 10 mm of drop allows the gun to be mounted quickly when the gun is brought up to the shoulder from a lower starting position such as in a hunting scenario.
Monte Carlo stocks on many trap guns (as discussed last month) have no drop in the comb. They may be 35mm for the entire length of a 120mm comb and have a sharp 10 to 30mm curved indentation cut into the last 20mm of the comb to help position the recoil pad correctly into the shoulder.
Going back to what is considered perfect for yourself is an argument that is fruitless unless someone who knows how to fit a shotgun is actually there with you watching how you physically mount the gun to your shoulder and watching where the comb sits on your face underneath your master eye. I have seen shooters with very high cheekbones have stock dimensions of 26mm, which fit them perfectly. For some shooters the gun is best suited to have a comb much lower. Somebody that is quite bulky in their face may need this or someone who has little or no prominent cheekbone to place the comb underneath and will therefore have to rest the guns stock beside the upper part of their jaw bone. Everyone is built differently so correct fitting on this part of the stock is of paramount importance for accurate and consistent shooting.
Finally if you are going to try to shoot the one stock and one shotgun for both Trap and Sporting Clays try to buy a stock with an adjustable comb. Set the comb at its very lowest setting for sporting and then you can raise the comb to better handle the fast rising clays that trap shooting provides.