Range Design Considerations
There are many ways to develop the drawings for an indoor gun range. Here are the most critical items to consider when planning your new facility:
How much space should I allow for my range?
Several key factors need to be considered to insure sufficient length, width, and height for your indoor shooting range.
Length – Your required Length, looking downrange, is the sum of Get Ready Area + Shooting Distance + Trap Area + Trap Service Area. Here are the considerations for each of these components:
Get Ready Area – The suggested distance behind the Firing Line to the Rear Wall is 15’, with an absolute minimum of 12’. This measurement is from the Rear Wall to the Firing Line and not the back of the stalls. It is typical to have 2’ to 3’ from the Firing Line to the rear of the stall. If there are tables or obstructions on the Rear Wall, the Distribution Diffuser (if radial) should be moved forward the length of the obstruction. The distance from to the Firing Line is measured from the rear of the Diffuser.
Shooting Distance – Distance from Firing Line to Target. A commonly used distance is 25 yards (75’). But this can vary widely and depends on the clientele you will serve. In general, short distances are sufficient for defense training and handguns; medium distances for shotguns; and longer distances for rifle training, especially if your range will serve hunters and/or competition shooters.
Trap Area – You should be able to install any of the Steel Traps in 24’ or less. You’ll likely be able to fit most Rubber Berm Traps in 20’ or less. Talk to your preferred trap supplier for specific dimensions.
Trap Service Area – The Trap Area length includes 4’ behind the traps to allow for servicing.
Width – The Width of the stalls is very important from the cost standpoint. The wider the stalls, the more baffles, trap and ventilation will be required for the same number of lanes. This affects your startup costs as well as operating expenses for the life of the system. The smaller the width of the stall, the more economical the range will be to both install and operate.
Height – The range Height from the bottom of structure to the floor should be planned at 14’ with a Baffle and Safety Ceiling height of 8’. Once the ventilation and other components are designed, the roof can be lowered if space above the Baffles is not needed.
Section (Side) View of Range
Plan View of Range Area
Other Range Design Suggestions:
Vestibule – We suggest installing a Range Vestibule at the entrance of the range. This serves two purposes:
Help maintain pressure control for the range. The ideal range pressure is negative 0.05” as referenced to the Base Building Area.
Provide acoustical protection to the Base Building Area. If people entering and leaving the range keep one of the doors closed, gunfire noise from the range will not affect the people outside.
Doors – All doors should swing “out” of the range. This will hold doors to their seals with the negative pressure in the range.
Ventilation – The National Institute of Occupations Safety and Health (NIOSH) developed a standard for ventilation in 1975 that is the basis for all design standards. The suggested design criteria provide an average of 75 feet per minute across the firing line with minimal turbulence. The range is to also be designed with a negative pressure to the base building to contain contaminates where they were created and keep them from migrating to the base building. It is very important to have controls to maintain the required 0.05” negative pressure and let you know if the range goes positive. Sizing the Exhaust Fan with enough horsepower to compensate for dirty filters and the ability to modulate to maintain the negative pressure as the filters load is very important. Here is a design checklist for the Range Ventilation System:
Range System designed for 75 feet per minute
Range controls will modulate exhaust based on filter condition
Range is designed to maintain 0.05” negative pressure
Range Exhaust or Recirculation is filtered with the final stage of filters a HEPA filter that removes 99.97% of contaminants
Proven distribution system that will provide laminar or even flow at the Firing Line
Hearing protection – Acoustical considerations are important in a range. There are two issues with sound. The first is the exposure to the occupants of the range and the second is the sound that can escape the range envelope. The occupants of the range should be exposed only to sound that is below the OSHA required limits. The sound should not cause exposures that are uncomfortable in the base building and below the allowable levels at the lot line (property line) as set by the local municipality. We suggest that you work with an experienced Acoustical Sound Engineer to insure both the comfort for the occupants and local code compliance.
Baffle layout – A typical 75’ range with a fixed Firing Line requires 9 or 10 rows of baffles. However, if your range will be used for tactical training that involves shooting from various downrange positions, the baffle layout must be designed to protect the downrange breathing zones. This requires significantly more baffle rows, perhaps as many as 22, and the airflow needs to be contained below the baffles with block-off plates that go from baffle to baffle.
Ballistics – Make sure the baffles, traps and other ballistic components are designed both for the type of ammunition to be allowed and the volume of rounds fired. Higher caliber ammo and/or higher volume requires models and brands that are specially designed for this type of use. Check with your ballistics contractor for the best trap for your facility.