First remember that FPS is a headline number, so unless you understand the associated joules, BB weight, site chrono rules etc. then you’re likely to end up buying a rubber of spring that doesn’t deliver as promised.

It’s the headline number for airrifles, the number in the largest font on the box, the number that makes the most impression on beginners and novices alike. And the most commonly misunderstood figure of all – velocity in ft/sec is only a guide as to the speed of the BBs, it tells you nothing about the energy transferred to the target and even less about accuracy.

FPS depends on the BB you use

Note also that a riflemesured at 400 FPS using 0.20 g BBs will most likely read lower FPS with0.30 g BBs and higher FPS with lighter BBs. As for the energy in air, it’s more or less the same, just mass vs. speed.

First, FPS is a headline number and needs to be understood in terms of BB weight (see earlier). Moreover, most chrono limits are in terms of a specific BB weight. So, for example, if a site lists a chrono limit of 400 FPS but does not specify BB weight then ask for confirmation. A rifle tested over chrono with 0.20 g BBs (light weight BBs) could easily go over limit with 0.32 g BBs.

What the numbers mean in practice

  • 300 FPS and under: Short range engagements in indoor areas etc.
  • Approximately 350-400 FPS. Ideal for general outdoor gameplay, such as tactical missions across wooded sites.
  • Around 400-450 FPS — sniper rifle limits at most of the woodland sites. Minimum engagement distance often is 20-30 meters.
  • Over 450 FPS: for the very occasional game and then only if specifically allowed as part of a designated team playing at a 20-30m minimum range.

Range is a different problem

Remember though, FPS is just half the story when it comes to measuring the performance of airsoft guns. Also taken into account when working out the effective range of a particular model is the BB weight, air seal, hop-up quality, and even the quality of the barrel.

This is why you will find many experienced airsofters have spent a lot of money on things like hop-up rubbers, quality airsoft barrels, and air seal.

Chrono etiquette

Just as important as remembering to take your chrono to the field is to read off your rifle before every game. A lot can happen between games to affect the velocity of your gun: Spring relaxation, hop-up slippage, changes in temperature and even wear of air seal components. Always try to have some idea of what your gun is reading before approaching the chrono stations at the sites. If you are over the site limit for any reason, don’t argue just go and re-jumper or re-hop for the remainder of the day.It doesn’t take long to loose the goodwill of a site if you’re seen to be causing problems at the chrono.

Start with field rules

Make sure you understand the Field Rules (Chronograph Limitations, Min. Engagement, Full-Seal Eye Protection, etc. etc. – and yes they vary – frequently between regions and individual sites. MFG Specs are a good starting point for anyone purchasing a new gun and adjusting the spring, but in reality BB weight, initial velocity,BB config, temperature and general maintenance all affect the Measured Energy of any given airgun.

Treat protective equipment as part of the system

When on the playing field do not forget your protective eye wear, ensure that the masks are comfortable so that you can still keep an eye on things when in play. Lens strength and simple cleaning of your goggles etc are also points to note. Maximum comfort will lead to better decisions on the playing area.

How to evaluate the advice

To verify advice for airsoft rifles to buy, look for mention of the following measured facts: The weight of the airsoft gun, length of the airsoft rifle, the number of magazines for the rifle and the chronograph test results for the Spring. Note that the advice-giver’s preferences regarding the trigger, overall feel of the gun, the stock’s fit, extra features of the rifle, how it looks, etc. are all mere opinions. These are also often written as ‘Reviews’ or ‘Ratings’.

A sensible next step

For beginners, a good idea is to start by writing down the limits of the field you play on, your in game role, and what problem you are trying to solve. This helps in testing one change at a time, which can be very expensive if you purchase a lot of upgrades that don’t work in the end.

Legal and practical responsibility

Airsoft replicas are toys. They must be treated with the same amount of respect as real guns. In most countries there are strict local laws as to the purchase, appearance, display and use of airsoft replicas in public. Replicas must be transported in appropriate cases and never displayed in public in a threatening manner. Check the local laws with the appropriate local authorities before purchasing an airsoft replica to see if you are allowed to use it in public.

Read specifications in context

Velocities, ranges and accuracies published by a manufacturer are hardly ever based on all possible combinations of test parameters (BB weight, air temperature, hop-up, barrel quality, etc.). Fields and routes, for which a replica was tested, often are quite short and not very demanding. Product dimensions quoted by a manufacturer need to be seen in context as well. These are usually measured without any additional gear (optic, bipod, sling, loaded magazines, etc.). Repeatable field tests and owner experiences therefore are more important than a single figure. And it must be weighted against the replica’s reliability, spare parts back-up and how well the gun fits the player.

Plan upgrades in stages

The first upgrade that you make to your stock Airsoft replica should be to make sure that it is clean and working properly with the standard hop up setup. After that, test a number of different weight BBs to see which give the best results for your type of play. As you progress with your replica and make further upgrades, make sure that you test the upgrades one at a time so that you can see what effect each part has had. This will also help to identify any problems with individual parts and will ensure that you are working within the field limits of your replica. Cosmetically enhanced replicas can then be upgraded as you see fit.

Make the equipment easy to live with

It is best to set up your Airsoft gear to be as easy as possible to transport, to set up and to maintain. Label your magazines, keep your batteries or gas in good condition in accordance with the manufacturer’s recommendations. A small first aid kit of cleaning solutions etc. should be kept in your airsoft kit to make any last minute adjustments just before a game. After the game make sure all fasteners are secure, check sling, optic and other equipment for any sign of wear or damage before stowing the lot away until the next time you go out and play.

Field checklist

  • What is the energy limit for Airsoft on the Field? And what is the shortest engagement distance on the Field?
  • Make sure to use adequate eye protection. Check your goggles and masks before heading out to play.
  • Use the same BB weight and the same hop up setting as you intend to use when playing on the field.
  • Document changes, so that positive changes can be repeated and in reverse order where required.
  • Immediately stop using any item that suffers damage in a game until it has been assessed for safety and subsequently repaired where required.

Final perspective

The evaluation of Airsoft FPS and Field Limits is most useful if you consider it within the boundaries of a complete playing system. After all, a long list of improvements for your replica is of little use if the basic functions are not reliable, if the replica does not fit you well and if you are not able to handle it safely. Test your equipment carefully, stick to the field rules and choose your replicas and accessories based on your real way of playing Airsoft.