Article 9 – 2016
Question: I was given a copy of your recent article in the Australian Shooters Journal (ASJ) about how to pattern a shotgun. I found it really enjoyable and used your advice to the test my Beretta and have been surprised by the results as to where my shotgun actually was shooting. The question I have for you is what is the perfect distance to actually pattern test the firearm from? I was always under the opinion that this distance was to be 40 yards. Why do you not advise this?
Robert Caple, Virginia SA
Answer: 40 yards (36.5 metres) is still considered the most desirable distance to ascertain the performance of any trap or hunting shotshell through the barrel of the firearm you will be using. At that distance judgment calls can be made to see how the velocity of the shotshell may be blowing the shot pattern apart or alternatively holding the pattern together. The performance of the shot, wad and choke of the barrel can also be made by actually counting the percentage of pellets that remain in a pre determined defined diametre which at 40 yards is generally 30 inches. (Sorry for the imperial measurements, but often shotshell performance is still solely spoken about in this form.)
The article you are referring to in the recent ASJ was specifically written about making calculations and alterations as to the point of impact above, below, left or right of a defined aiming point. It makes no assumptions on the performance of the shotshell. Most shotgun shooters have no idea where their firearm is throwing its payload of shot in relation to the target. Because shotgun shooting has a fair degree of margin for error many shooters never bother to take the time to walk down to a pattern board at their local club and ascertain where their gun is actually shooting.
I advise people to test their accuracy at no more than 18 metres (20 yards) as holding a shotgun as steady as a freehand rifle shot is very difficult for most people that are not use to the steadiness of hand required to perform this task accurately. Obviously the further you move back from the pattern board then even the slightest barrel movement will give a false account of your shotguns true point of impact.
Remember the shot leaves the barrel and spreads in a fairly symmetrical cone formation so the percentage above, below, left or right of the target will remain constant until around 55 metres (dependent on shot size) when the effects of gravity start pulling the shot towards the earth.
Interestingly many Americans test their trap shotguns at only 13 yards as they say this will give them an even greater level of accuracy, which indeed is true. The only issue I have with this distance is often the shot really hasn’t had enough time to spread quite wide enough through tight trap barrel chokes therefore making an accurate estimation difficult. Also the powerful impact on the clubs pattern board will tend to be harsh at this close distance.
An important thing to understand when patterning your shotgun is to mount the gun to your shoulder and place your face on the stock in EXACTLY the same manner you do when you are on the range or in the field. If you are doing this pre-shot procedure differently when shooting at the pattern board then you are simply wasting your time. I see many shooters that have a very aggressive gun mount when they are actually shooting competition under pressure, but when they go to the test their firearms they fire at the stationary pattern board they change to a very deliberate and soft gun mount. This often means their face is not as locked into the stock of the shotgun in the same way that it is when on the range that in turn will mean their shot on the pattern plate will be higher and in many cases further to the right (for right hand shooters).
One last piece of advice is to fire three shots from the same barrel one after another when patterning your shotgun. This will give you a pretty decent “average” pattern to make your assumptions on and will obviously discount any small mistakes due to “pulling” the shot slightly away from the aiming point. Again it is important to remember we are only looking for a percentage relative to the aiming point.