by Hap Rocketto
Smallbore rifle shooters, particularly prone ones, actually all shooters, are always on the hunt for something that will reduce group size. The quest for the Holy Grail of a ten shot 0.50 inch group at 100 yards usually begins with testing lots and lots, of lots of ammunition. This quest can reach monumental proportions, for example; I have a friend who budgets $1,000 a year just for test lots. Once the best grouping ammunition is found one buys as much as the purse will allow.
Centerfire shooters have a great accuracy advantage as they are able to roll their own, using a near infinite number of combinations and permutations of powder, ball, primer, and case to attain the best possible group. Rimfire benchresters, prone, or position shooters are not as fortunate as they must use what comes out of the box and are held hostage to the ammunition manufacturers.
Once a tight shooting lot of rimfire ammunition is found many benchresters go a step further. They tune their barrels by moving weights back and forth on the barrel until a “sweet spot” is found that further reduces the group size. Unfortunately the “sweet spot,” like the Earth’s field magnetic can, and does, change. It is susceptible to different lots of ammunition, temperature, humidity, and density altitude to name a just few factors.
Some rifles will be very stable and hardly ever need the tuner to be moved while other will need to be tweaked from day to day. Barrel tuners are very common in the benchrest community and have had a growing popularity with prone and position shooters.
I have never warmed to the use of tuners in prone and position shooting for several reasons. Understand, I do think that they might work, certainly for bench rest shooters, but as a position shooter I have not developed a hard enough hold standing to offset the extra weight and surface area of the device. Although tuners, which are integral parts of bloop tubes, have been developed which partially mitigate this problem.
On top of that they have to be adjusted each time you shoot and there just isn’t enough time in a match to be fiddling with tuning.
A third reason is that it often takes a considerable amount of expensive ammunition to find the correct setting, which may not be the correct setting the next day.
Some very successful shooters have started to use tuners. Lones Wigger is one. Tarl Kempley, a talented shooter and engineer has developed his own design called the “Beesting” which he uses successfully. Eric Uptagrafft, a rifleman with the Army Marksmanship Unit, has a small sideline business which produces, among other things, a tuner tube which was attached to the rifle he used in the 2012 Olympics.
As a side light Uptagrafft’s wife Sandra was also a 2012 Olympian, shooting air pistol, the second time a husband and wife were on the same US Olympic Shooting Team since Ken Johnson and Nancy Napolski-Johnson participated in the Sydney 2000 games.
My third reason is based upon a personal experience. Some years ago, desperate to improve my rather pitiful prone scores, I purchased a tuner. I was short of cash and had to settle for a rather inexpensive one made in an Eastern European country by a firm called Operknokiti GmbH and Co. Pty.
The directions were printed on a multifold sheet of cheap thin paper. The multitudes of languages were printed in a barely readable light gray print. To be charitable, the English translation was rather poor. It read like a translation contained in a package of disposable Elbonian razors, “Smuggle the razor blade (reference value around 400 g) on your muscle vertically, then drag your skin and shave back slowly.” Any father who has struggled into the early morning hours of Christmas Day trying to assemble a toy made in a foreign country for will appreciate the problem.
I first matched up all of the parts with the schematic which reminded me of an example of Abstract Expressionist Art. Carefully I assembled the parts and then placed the tuner tube on the muzzle of my rifle.
After tightening the set screws to hold the tube, I fired a group. I then minutely adjusted the weight up and down firing a group at each stop until I got the tightest knot, about 250 rounds later. I then recorded the setting, lot number, temperature, humidity, density altitude, wind condition, torque of the screws, date, time of day, my height and weight in the metric system, and astrological sign as required in the accompanying data sheet. Following the instructions I tightened down the weight set screw and locked it in place with the Balkan equivalent of Loctite, which was enclosed for the purpose.
Not surprisingly when I tried to test another lot the next day I found that I could not loosen the weight set screw to adjust it.
It was impossible for me to test any more ammunition and I was stuck with the setting on the rifle.
I had learned a shooting truth the hard way.
Operknokiti only tunes once.
