Q: Why do you use rubber membranes, which require maintenance? Isn’t it simpler to have the sensors attached to the outside of a conventional target?

A: The rubber membranes form an acoustic chamber that isolates the sensors from numerous environmental effects which are detrimental to accuracy and reliability. The chamber is precisely described in the article Acoustic chamber targets: what you need to know. In fact our very first experiments with projectile detection were with sensors mounted outside a conventional target. It did work, but there are significant problems with accuracy and reliability, namely:

  • The dramatic error due to impact angle variation can be for example 7 cm at 300 m, or 13 cm at 900 m.
  • The Doppler Effect, caused by wind, can result in errors up to 5 cm
  • Parallax error, where “conical” soundwave from the projectile is distorted due to environmental effects, or where the shooter’s position is not perfectly aligned with the target; these errors can be of the order of feet, dependent also on projectile speed
  • Interference from projectiles firing on nearby targets, and other external noises.
  •  Accurate positioning of the sensors is critical to accurate performance, which is difficult to ensure on a conventional target frame. HEXTA target frames are designed for rigidity and built to high tolerances.

During our market research, the clear message from all shooters was that they would not compromise accuracy and reliability for a cheaper product. So we went for the “chamber” design. Our aim has always been to minimise errors wherever possible.

Please refer to the article Acoustic chamber targets: what you need to know and question “We are able to manufacture wooden target frames ourselves. We would like to get an estimate for supply of electronics, software, sensors, wireless connection, cabling etc“

Q: What is the accuracy of HEXTA targets?

You can find our accuracy results <here>.

We publish our accuracy results because we are confident of them and we stand by them. If you are shopping around, we strongly recommend you ask each supplier to provide accuracy results they are prepared to stand by and be tested against.

Important: The accuracy test on chamber-less target systems quite often is obtained in ideal chamber-like conditions, without any interference from the ‘next door’ target and real environment. Learn independent test results from different sources. You may find some here.

Q: How can you be sure that interruptions in communication or electromagnetic interference don’t result in lost shots?

A: The HEXTA system is engineered to minimise the risk of lost shots by every possible means.

  • Unlike our competitors, HEXTA has 8 acoustic sensors in each target¹, which provides redundancy and dramatically reduces the chance that a shot will not be detected at the target. For more explanation on this question, see our article “HEXTA statistical analysis and correction”¹ and Why four is not enough”
  • The signal from each acoustic sensor is processed and digitised at the sensor, so the signal transmission – all the way from the target sensor to the user’s monitor – is fully digital¹, with extensive redundancy and error checking. This design is vastly more resistant to electromagnetic interference than systems using analogue transmission from the target to the target controller, where the target cables can act as antennae and are affected by electromagnetic radiation.
  • The RF LAN transmitter, between butts and mound, uses ‘spread spectrum’ technology, thus eliminating potential interference from constant-frequency sources
  • Using TCP-IP protocols with multiple, bidirectional confirmation of data delivery, the effects of wide-spectrum interference are minimised.
  • Shot data is stored in target buffers, so that in the event of momentary drop-out of the LAN connection the shot data is automatically retransmitted after the link is reestablished.
  • HEXTA constantly checks the health of its subsystems. In the event of a problem, a warning will appear on the user’s monitor.
  • The targets are as independent as possible, so that a problem with one target will not affect the others.
Q: What about multiple shooters per target?

A: Early in the development of the HEXTA targets we realised there are fundamental physical limitations with multiple shooter technologies.

Multiple shooter or “multi-point” systems using muzzle blast detection depend on the time of flight of the projectile. Shooters know that in reality muzzle velocities vary considerably between rifle types, ammunition types and loads. Even in a series of consecutive shots from a single rifle there are random variations in velocity. This means that if two or more shots are fired almost simultaneously (a common occurrence) the system will be unable to determine which shot arrived at the target first.

The problem is worse at longer ranges. At 900 yards, if two shots are fired within about 0.5 seconds (you can easily pick this by ear), the system should give a warning that the shots are “too close to call”¹. Products currently on the market give no such warnings, thereby exposing shooters to the risk of incorrect results. If proper warnings were provided, you would soon get sick of them!

The overall lifetime of a target is dependent on the total number of shots fired on it. With a multi-point system you have fewer targets to maintain but the target lifetime will be shorter by the same amount. The initial outlay of the system may be less, but you’ll be replacing targets sooner.
Similarly, maintenance effort, maintenance frequency and costs are in proportion to the total shots fired, so there is no saving with multi-point.

In the end it’s a zero-sum game. And this needs to be taken into account in budgeting for your system.

For more explanation on this question, see our article “Shared-target shooting on electronic targets”

Q: Is an 8-sensor target more accurate than a 4-sensor target?

A: Absolutely.

An 8-sensor target has a much greater level of redundancy – it makes 56 estimates of position for each shot, compared to 4 estimates with a 4-sensor target. This means that a single faulty sensor reading will have a much lower influence on the accuracy.

Not only that, the HEXTA error correction software identifies and eliminates faulty sensor readings. This is impossible with a 4-sensor system .

An analogy would be a GPS system, which uses the same principles as an electronic target – the greater the number of satellites involved, the greater the accuracy of location.

You can read more about this in our article “HEXTA statistical analysis and correction”¹

Q: Is an 8-sensor target more reliable than a 4-sensor target?

A: Absolutely.

Again, this is due to the high level of redundancy.

Statistically, an 8-sensor target has hundred thousand times lower probability of an unregistered shot than a 4-sensor target. In other words, the risk of a target failing to register a shot has been virtually eliminated. In effect, this means that if the shot did not register, it missed the target!

Q: Why is the frame larger than required 2400×1800?

A: Our frame is 20cm larger (2600x2000mm) than prescribed by Standard Shooting Rules (SSR’s). The standard prescribes for 700m and above distances target dimensions to be 2400x1800mm. According to the same standard if the shooter missed the “outer two”, but hit the board, it counts as “1“. So the whole area of 2400×1800 must be a sensitive area, i.e. the sensitive sound chamber must be 2400×1800 plus an extra margin, surrounded by a rigid frame. At the same time the target frame must be rigid as any type of flexibility due to wind, installation tensions, changes relative sensor position and compromises the system accuracy.

1. The standard prescribes the hit area 2400×1800 is counted as “1” so the manufacturer should follow the standards.

2. Feedback obtained from top-class shooters mention competitions could be performed at severe wind conditions, where the bullet may be blown even to the next target. In this case everyone is affected by similar bad wind conditions and even “1” is very common and could make a difference at the end of the match.

Q: We have only a 600 metre range and we want 1800×1800 frames.

A: We also offer  1800×1800 frames if required.  The differences in the dimensions, price and weight between 1800×1800 and 2400×1800 frames are not significant.
We would like to mention that the 2400×1800, 1800×1800 are the shot sensitive areas (without any exception even in the corners). To achieve the sensitive area of 1800×1800 we have to use a larger frame 2000×2000 (extra 10 cm from each side to allow for the internal sensitive chamber). The same applies for the 2400×1800 frame size.

Q: Can we build our own target frames and install your electronics?

A: HEX Systems is aiming at building the world’s highest accuracy shot recognition system. The frame is actually a functional part of the system. It performs a number of important functions. HEX Systems invested significant effort in the frame and chamber design. The chamber has rubber membranes and the internal chamber attenuates external noise and compensates for internal ultrasonic resonances, minimizes temperature measurement errors and forms the proper front surface for the projectile’s shock wave.
We had a number of requests to sell the electronics and software only. We have extensively discussed this topic and established a Company Policy to not sell electronics for mounting on custom built frames as we cannot afford to lose quality control of the overall system.

Q: Does HEXTA indicate pinholes?

A: Yes. In fact the user may configure anything: the ring number, dimensions, colour, thickness etc, shot value, indication etc. The pinhole is the ring with 5mm. (configurable) diameter.

Q: Do you take in account the calibre?

A: Yes. By default it has 7.82mm value (the Butts Officers gauge diameter, SSR’s)

Q: Does HEXTA display the actual bullet hole diameter on target plots?

A: HEXTA calculates scores based on the measured shot position and the ICFRA standard gauge (7.82mm diameter).
The HEXTA monitor shows the bullet hole as a black ring. The inside diameter of the black ring as close as possible to the correct gauge diameter (7.82 mm for ICFRA targets). So the black ring sometimes touches the line when the bullet itself has not.
On the HEXTAweb online database the shot appears as a colour-filled black ring. This disc is significantly larger than the actual size so it would be visible on printed document.

Q: How do you address the different aiming marks on the same target frames?

A: HEXTA targets are supplied with a set of removable aiming mark panels – one for each range distance. The panels are attached to the front face of the target with velcro and are easily changed.

Q: How is the system powered? We do not have mains power on the range.

A: All components of the system are battery powered. You will need mains power to recharge the batteries. Solar power can be used to do this if there is no power on the range.

Q: Someone else put a shot on to my target. What do I do?

A: The Master (Scorer) Monitor has a “Disclaim” Button. When it is pressed, the scorer can select shots and converted them to and from the next consecutive letter after the sighter shots (A. B C etc). The shots marked with letter would not count in the final score.

Q: What happens if I miss the target?

A: The current system does not have a muzzle sensor however it is in our development plan. The Master (Scorer) Monitor has a “Miss” button, which adds the shot with zero value to the scoring table.

Q: How do the multiple monitors works?

A: The range has Wi-Fi network. When you login to the Wi-Fi network your device becomes part of the local network. With your browser you select the webpage on the web server, which is managing your browsers requests¹.

Q: How do the Master and Slave monitors work?

A: The systems software can be run in two modes: the Master (Scorer) mode and the Slave (Spectator) mode¹.
When the software is started in master mode, it will ask the user the range distance, target number and become dedicated to the selected target. Only one master may be active per target. Master mode can be used by the shooter or check scorer (depends on agreement). Apart on Slave mode, In Master mode user can enter the shooters club, name (or later UIN), Stage, Class (Full Bore, F-Class etc,). Also shooter may change number of shots, number of sighters. In the master mode the shooter or check scorer controls scoring process, like cutting sighters, set the miss or disclaiming a shot¹.
In Slave mode the monitors are not dedicated to one target. Observers have additional options to browse all the targets and all the previous sessions. The information about Club, shooter, sessions, class and current or final score will be displayed to the observer. The observer has no option to control the shooting process.

Q: Can I use my own iPad as a scorer monitor?

A: The system allows using ANY systems as a monitor which has Internet Browser capabilities¹ with HTML5 and JavaScript support. Almost all current Wi-Fi devices are compatible. Note that some devices do not have fully compliant HPML5 and JavaScript and may be incompatible. Please check your device before buying.

Q: How do I check if the browser on my phone (PC, phone, tablet, etc..) supports Java script?

A:    With the device which you want to test, just go to the HEX Systems online score webpage  http://www.hexsystems.com.au/Hexta1.html. If you can see fully functional slave station, the browser supports our system.

Q:  Do you charge a fee to evaluate a customer’s range for suitability for your system?

A: No. We do help customers evaluate their range to optimise the performance of the system. We also assist customers in adapting the target mountings to the butts machinery. This service is provided absolutely free of charge.

¹ patents: US 9,004,490; AU 2013,101664; AU 2013,100,484; AU 2014,101,039