Airsoft Mechanics: Airsoft-Innovations Tornado Grenade

Airsoft-Innovations Tornado Grenade

Airsoft-Innovations (AI), the company well known for its propane adapters, has introduced the first reusable airsoft hand grenade with spherical BB dispersion pattern. AI claims that the Tornado Grenade is "the only combat effective simulation hand grenade." In this review, we will test its effectiveness and examine how it functions differently from the other airsoft hand grenades.

Introduction
For the longest time, there was never really an effective skirmishable airsoft hand grenade. The pyrotechnics based disposable units are frequently banned from the fields due to safety concerns, and the gas based reusable units are often inconvenient and typically outright useless. From inconvenient-to-recover self-disassembling parts to unstable timers to limited dispersion patterns, the current crop of airsoft hand grenades are simply ineffective in most skirmish environments. If the AI Tornado Grenade worked as advertised, it would easily outclass the competitions.

Package Contents
The AI Tornado Grenade package includes the grenade, valve cover, pull pin, valve key, and a detailed user manual, all neatly tucked into a compact card board box. The grenade and accessories are further sealed in text riddled plastic bags. A closer look reveals that they are legal disclaimer clauses. Similar writings can be found on the grenade body as well. We will discuss this a bit later.

Appearance and Construction
AI did not attempt to imitate any known hand grenades with Tornado Grenade's appearance . The unit measures roughly 54mm (2.128") wide and 130mm (5.122") tall with the valve cover installed. It is slightly larger than the common fragmentation or pineapple grenades. It is quite obvious that AI put the emphasis on functionality over cosmetic appearance.

The grenade appears to be well manufactured and assembled. The major components of the grenade unit consist of an aluminum core, polymer valve shuttle, and polymer outer shell. The parts are finely machined and molded without visible irregularities. There is also no apparent sharp edges or burrs that could pose as handling hazard.

Design
The Tornado Grenade can be considered as a miniature gas powered dual barrel shotgun. The interior of the aluminum core paired with the central polymer valve shuttle and bottom valve cover actually creates three separate gas chambers. The top most chamber is used for timing. The large middle chamber is the gas reservoir. The bottom chamber is the expansion chamber. The aluminum core's exterior combined with the two helix grooved polymer shells forms the two barrels, which double as BB reservoir tubes that hold 90 rounds each, or 180 rounds combined.

For a readied grenade, when the pull pin has been removed, the polymer valve shuttle would start to creep upward. The timing depends on the internal pressures, which are influenced by the temperature. Once the valve shuttle reaches the top, the seal between the middle and the bottom chambers is opened. The pressurized gas then expands into the bottom chamber and vents through the two ports that lead directly into the BB reservoirs. At which point, the BBs are forced out of the helix tubes. The ramps at each tube exit redirect the BBs upward or downward while the the grenade body goes into a spin from the opposite tangent discharges. The combined effect of both actions is the spherical dispersion of BBs.

Safety Features
AI has exerted a great deal of effort in designing and creating a safe product, and it shows. To prevent propellant over-pressure, which can produce unsafe projectile energy levels, AI implemented two pressure relief valves into the system. If the internal gas pressure exceeded the predetermined safety level for any reason, the pressure relief valves would open to bleed off the propellant. Furthermore, the grenade can be easily disarmed by simply taking off the bottom valve cover, thereby preventing accidental discharges. To minimize impact injury potential, the majority of the grenade is encased in the shock absorbing polymer shell. All edges are also rounded. Even the aluminum neck at the top has been covered with a rubber cap.

The safety features are all made to be relatively temper proof as well. However, it would be next to impossible to completely prevent user modifications. Furthermore, there is simply no way for AI to prevent users from misusing the product. These issues bring us back to the aforementioned legal disclaimers. They are there to remind users to be responsible with their own actions. It does not matter how safe the grenade was designed to be, in the end, the grenade would only be as safe as the operator. AI supplied all the necessary safety information on grenade operations in the user manual. So it is advisable for the users to read through the manual first before usage.

Usage
Readying the AI grenade is surprisingly simple. There are a total of 8 steps that can be completed in less than a minute total:

1. Remove valve cover.
2. Open top plug.
3. Reset main valve with the valve key.
4. Insert the pull pin to the desired time slot.
5. Charge gas.
6. Close top plug.
7. Load BBs.
8. Install the valve cover.

All steps are illustrated in the easy to follow user manual. Since the grenade is powered and timed by gas pressure, the performance unfortunately is affected by temperature. To make things easier for everyone, AI provided a nice chart in the manual detailing the pressures and resultant delay times of propane and HFC134a under the different temperatures.

Once the grenade is readied, using it cannot be any simpler. Just pull the pin and toss/roll the grenade towards the enemy. There are no parts to lose since the main grenade unit is effectively single piece. This makes retrieval extremely convenient.

Performance
I should mention that lubrication is vital to the Tornado Grenade's timer performance. Without the frequent lubrication, the timer would become prolonged and unpredictable. I find it best to service the polymer valve shuttle every 5 or 6 grenade discharges with 2 drops of silicone oil as indicated in the user manual. It ensures that the timer would maintain its consistency.

Due to the way that the Tornado Grenade functions, the velocities of its 180 projectiles vary from start to finish. Thanks to the pressure relief valves though, the projectile velocities really cannot go much higher than the listed 65 ft/s - 137 ft/s using 0.2g BBs. Repeated attempts at warming the grenade to achieve higher internal pressure in order to increase the projectile velocity always resulted in venting from the relief valves. At the short engagement distances that the grenade was designed for, higher velocities are really unnecessary anyway. Even with the relatively low energy output, the grenade filled with propane still provided a respectable effective blast radius of roughly 8 feet and a circular coverage area of about 200 square feet, enough to completely blanket a small room. Farther than that, the chance of impact decreases, and any impact would be less noticeable.

The grenade's safe low power output does present some challenges though. In environments with tall grass or other thick vegetation, the projectiles simply do not have enough energy to punch through the obstacles. As such, ground discharge in such environments would be ineffective.

Another notable issue with the grenade is its functional requirement of spin. In most indoor environments with few furnishings, the grenade would have no trouble spewing rounds in all directions as advertised. Once we move to the outdoor environment, ground discharge could become problematic depending on the terrain. The grenade's spin motion could easily be hindered by mud, exposed tree roots, and other environmental obstacles that could trap the grenade. Once the grenade's spin rate is reduced or even completely stopped, the projectile spread pattern becomes limited as well, thereby reducing the grenade's effectiveness.

Thankfully, the AI Tornado Grenade has an airburst feature that remedies both issues. Airburst, as the name states, discharges the grenade in mid-air. The feature is accessible either by setting the pull pin location to the 1.5s slot, or by simply "cooking" the grenade. The shorter timer causes the grenade to discharge before it lands from a toss. Since there is nothing to block the projectiles nor to disrupt the grenade spin in mid-air, the grenade retains its optimal performance in spherical spread and coverage. The feature is also great for engaging targets hiding behind covers.

Do note that the airburst feature can be just as effective on operator. Since there is no safety handle, AKA "spoon," on the Tornado Grenade, the timer starts as soon as the pin is pulled. So do not pull the pin until you are ready to throw. With the summer heat, this can be a big issue for those using the shorter timer setting. I had several instantaneous discharges using propane at an ambient temperature of 94F (34C) at the 1.5s setting. I have my own curiosity to thank for those though. The manual states that the 3s delay setting would produce 2s delay at 91F (33C) with propane, and I just had to see what happens with the 1.5s setting. So there you have it, high temperature plus 1.5s setting with propane equals no delay.

Conclusion
The AI Tornado Grenade is indeed the most effective airsoft hand grenade currently available. It has achieved everything it was advertised to do, provided that the users follow the supplied instructions. It is the only airsoft hand grenade that provides spherical spread. It has the largest discharge coverage area as well. It is also the only airsoft hand grenade with a relatively consistant timer. Even though the timer is affected by the temperature, the Tornado Grenade provides a repeatable time delay at each specified temperature. No other airsoft hand grenade comes in close to its performance. The US $99.95 price tag may be a bit high, but I feel it is justified by the design and build quality. The Tornado Grenade's innovative engineering and performance certainly stand up to the Airsoft-Innovations name.

Pros:

• spherical projectile dispersion
• consistent timer
• no loose parts to lose
• safe to operate
• durable

Cons:

• price
• temperature dependent performance
• requires frequent lubrication
• weak power output