Testing
We tested the gun for shot patterns and penetration before and after the barrel was cut. This was to see how much of the performance of the long barrel was lost in the process.
Due to time and ammo constraints we only managed to test one brand of ammo with two different shot sizes. The Baschieri & Pellagri F2 Long Range in sizes 3 and 4.
A standard patterning test was used as the testing method. The gun was fired from a supported position at a distance of 35 meters (measured with a laser rangefinder) into a large sheet of cardboard. A 75 cm circle is then drawn in the center of the pattern. After that you count the hits and compare them to the amount of shot in the cartridge, and finally you mark any major gaps in the pattern with a circle. We used the koeammunta.net -website to do the calculations.
When we originally shot the patterns with the factory setup, we had no idea we would have to change the type of choke tubes on the gun and that we would only have the one IM-choke available at first. So that’s why the 24″ barrel patterns are shot with the MOD -choke and the 14″ barrel patterns with the IM -choke.
After the patterning we shot the penetration tests to dry pine boards from 30 meters. This was not a good way to do the test and we only got rough measurements for the penetration. It was difficult to measure exact depths with the uneven surface of the board using a needle and a caliper as the measuring devices. So take these results with a grain of salt.
The Results
These are the patterns that were shot from the 24″ barrel. Size 3 on the left and size 4 on the right side:
Below are the patterns from the gun after the barrel was cut to 14″:
So what conclusions can be drawn from the results? The factory barrel seems to pattern more consistently with both rounds, but the shortened barrel produced a better group with the size 3 load. With this small of a sample size there is not much data to draw from. There is one important thing that can be stated: The short barrels can produce as good patterns as the longer ones, so the patterning is not a very good reason to carry a hockey stick sized gun in the woods. There are also a million and one different ammo / choke combinations out there to try out and find the perfect combination for any gun.
What about penetration? With the size 4 load we measured about 6,5 millimeters of average penetration for both barrel lengths. With the size 3 load the same number was around 8 millimeters. There was not a lot of deviation between the different barrel lengths, so it’s safe to say that at least with these loads you do not lose a lot of terminal ballistic performance by shortening the barrel.
So here are the preliminary results. At least we are relieved for not having to buy a new barrel to the gun, which we would have had to do if the performance would have not been there.
In the future we will be doing a lot of clay training with the gun to get a feel for it. We will also be experimenting with lead free ammo, and we’re definitely going to be shooting more with slugs after we get the red dot sight on the gun.