Note : Apologies for the pics. I used my phone and managed mostly to get partial pics of feet, bushes, cows in the next field, etc. Everything but the intended thing to be photographed. Unfortunately this has resulted in much less pictures than originally intended.
OK, so my old chronograph finally died after months of faulty readings or flat refusals to work. I was tired of the same optical types which required firing between the poles and could only really measure velocities at the rifle; not further down-range. A bit of research and advice from friends led me to the SuperChrono Accoustic Chronograph. Essentially a chronograph that measured velocities acoustically by measuring the crack of the bullet as it travels across two sensors. Promised benefits included:
- No more limitations in poor light.
- No need to shoot between poles.
- A much greater readable area (approx 60 inches above the chrono and 31 inches either side).
- The ability to place it anywhere along the bullets flight in order to confirm velocities at different distances.
- Can be used regardless of weather and light conditions, including rain, snow and fog.
Approximately $380 dollars later and the parcel arrived at home. Removal of the wrapping and bubble wrap and I discovered the unit packaged in a vac formed blister pack, complete with cardboard backing card which unfolded to show instructions on both sides. Instructions which were brief and straightforward. Despite the purchase price, the packaging does not instil one with confidence and quality.
The unit is supplied with an allen key (metric size) which is used to remove the battery pack lid and install 4 x AA batteries (not included). Thereís also a threaded hole on the underside with which to fit a photographic tripod. Thereís also a sticker repeating the siting instructions for those who couldnít be bothered reading the original instructions or have forgotten.
Iíve recently acquired a Remington 700 in 22-250 which iím having problems working up a load for so decided to bring the chrono along. The day was winds of between 30-40mph, gusting to 50s, showers and poor light conditions. Ideal for testing its capabilities.
I set the chrono approximately 40yds from the target and then withdrew a further 150yds approx. The handheld laser read 192yds in total. The chrono has a pair of sights similar to those found on a lever action rifle, mounted at the front and back. Provided you sight along these sights and position the unit in line with the bullets path, it will record the velocity of the bullet as it travels over it. The only other consideration is ensuring that it is level. This is helped with the addition of a small spirit level positioned on the top face.
The chrono will read the velocities in either feet per second (ft/s) or meters per second (m/s). You can switch between both without fear of losing your readings at any time and an average will be calculated upon pressing the average button. Just remember to clear old readings by pressing the reset button. I didnít and got thoroughly confused.
At the end of the day my friends and I had successfully recorded velocities using calibres including .243, .223, .308, 22-250 and 25-06. The only failures occurred when we deliberately acted like numpties and attempted to confuse the unit.
How could we cock up and how far could we deviate from the instructions in order to confuse the chronograph? We began by leaving the unit uneven. The readings didnít change substantially until the front was elevated to approximately 20 degrees. By that time it was reading 200-300 ft/s less than expected. However the easiest way to confuse it was to change its direction from that of the bullets path. We aimed it 45 degrees from the bullets path and in doings so reduced the recorded velocity by approximately 1000 ft/s !
Shooting either side didnít seem to change effect it much. We eventually worked out to stupid distances of approximately 4ft either side of the target before concluding that anyone shooting so badly has no right to own a rifle in the first place.
Iíd love to be able to tell you that all my shots resulted in a neat little clover leaf on the target and that I went home with a big smile on my face. The chronograph performed faultlessly but I didnít. My 22-250 load consisted of 52gr Hornady Amax bullets, CCI primers and 35.5grs of Varget. Unfortunately the velocities ranged from 3605 Ė 3632ft/s which resulted in bullets scattered all over the 3.5 inch target at 190yds. Obviously iíve messed up my reloading somewhere.